The Next Chapter

Today we are excited to announce we’ve raised a $4million Series A investment led by Qualcomm Incorporated, through its venture investment group, Qualcomm Ventures. As we’ve got to know Qualcomm over the past few years it’s become clear that they are the right partner for the next stage of the OpenSignal journey, as not only are they leaders in the wireless industry but they also share our belief in the potential of sensor networks and crowdsourcing.  We’re looking forward to exploring this burgeoning field together and happy to say that O’Reilly AlphaTech Ventures and Passion Capital are also participating in the round.

Our core mission remains the same: Consumers around the world spend more than a trillion dollars every year on wireless contracts/plans and although network quality is the single most important factor1 for them, there has never been a source of independent and unbiased data they can rely on.  Our goal is to upend the information balance in this industry and provide consumers with accurate data so they can choose the operator that will provide the best coverage for them.  This increased transparency should also lead to more competition in the wireless industry and encourage operators to invest more in providing better coverage and performance – and we’re already working with operators on every continent to help them improve their service by leveraging our data.


The increasing number of sensors in successive generations of mobile devices

However, in building a sensor network for wireless signal we’ve become fascinated by the possibilities that now exist with the explosion in sensors on mobile devices that can measure anything from your location to the atmospheric humidity.  The next generation of mobile devices will extend this to include things like air quality, radiation and 3D vision sensors to name just a few and with 2 billion smartphones now in circulation there is an enormous opportunity to tap into these to build sensor networks at a scale that has not been previously possible.  In addition to growing the OpenSignal sensor network we’ll continue to experiment with WeatherSignal, our sensor network for the weather, and building new networks that tap into entirely new sensors – watch this space!

We’ll be using the funding primarily for growing the OpenSignal team and are particularly looking for people that like data as much as we do, whether it’s mining datasets for hidden correlations, telling stories with intuitive visualisations or building a scalable pipeline for handling large volumes of data. If that sounds like you then we’d love to hear from you.


Read more on the Qualcomm Ventures website.


[1] “OfCom Consumer Experience Report 2013”: 9.1.4 Poor coverage and Quality of Service are the two most important factors mobile consumers complain about.

Posted in Press, Sensors, Team, WeatherSignal | 10 Comments

OpenSignal for iOS: The Remake

Last week we released a new version of the OpenSignal app for iOS. This version had been in the works for months, with a complete overhaul of both the design and functionality – to produce something that would better fit the design schematic of iOS7 and bring the app’s functionality up to equivalence with the Android version of OpenSignal.

The first few days after the launch have been a great success. We got great press from The Next Web and Slashgear, were featured by Apple in the App Store in 91 countries worldwide and have already seen great engagement from users making use of the new sharing options – with lots of speed tests popping up on twitter. To give you an idea of how quickly we saw app use spreading over the world – this graphic was whipped up by our developer Pau, showing all the places we’d received data from users of the new version from within only the first 6 hours of launch:

ios app locations
For those of you have yet to download the new version, it is drastically different from the previous version – with there being three main areas of differentiation.

1) Improvements to user contribution: we make use of enhanced permissions in iOS 7 to bring up user sharing to a level similar to that of the Android app. This was a much-requested feature by our users, but impossible due to iOS permissions before now. We now allow (depending on user settings) background data collection (the app checks network type when the iOS system itself detects a significant change in location). This means that users can now contribute much more to our crowdsourcing project, and therefore to the coverage maps we publish on this website

2) Better stats for users: one of the features users often request is better information on their actual network performance, often so this can be used when talking to their service operators. The new in-app stats show you how your network has been working for you over a set period of time (for instance, what % of the time you have had a 3g connection over the past day/week/month). We also let you see how your stats compare to the average global OpenSignal users – to put your experience of mobile connectivity into context.

3) Overhauled UI: The app looks completely different, with a much cleaner and more intuitive interface and this makes it much easier to improve your signal/find nearby Wi-Fi networks (we’ve also improved our Wi-Fi recommendation system, making use of foursquare data to, in some instances, tie free Wi-Fis to their locations.

We hope you like the new version!



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National Roaming: How much impact would it actually have?

Note: An earlier version of this post contained a graph which contained a small error. It has now been updated

This weekend, Sajid Javid, the minister for Culture, Media and Sport announced plans to engage in talks with mobile operators in the UK to establish a ‘national roaming agreement’, whereby operators would consent to share their mobile network infrastructure in order to maximise coverage. The cause behind this announcement appears to have been David Cameron’s failure to get a good mobile phone signal while on holiday in Cornwall, alerting him to the realities of mobile network connection in much of the rural United Kingdom.

This announcement achieved a great deal of publicity in the UK press, including some rather overexcited responses (the Times’ front page headline ran ‘End to mobile phone blackspots across UK’), but in none of these articles was the actual impact of a national roaming agreement analysed quantitatively. A national roaming agreement, while increasing network coverage for all networks, would not put an end to mobile blackspots as networks have a great deal of overlap in terms of their areas of provision. Using OpenSignal data gathered from over 40,000 users across the UK we are able to say exactly what impact a national roaming agreement would have, were one to be put into place.

The Average UK user has no signal 7.7% of the time, under national roaming this would drop to 4.9% – a huge improvement, but in no way an ‘end to mobile blackspots’. National roaming would impact the discrete networks to slightly differing extents, as the following graph demonstrates:

The impact of national roaming

The impact of national roaming

The metric we use for analysing this is our coverage metric ‘time on no signal’, which looks at the proportion of time the average user has no mobile phone signal (2G or better). A part of ‘time on no signal’ includes a subset called ‘time on emergency calls only’ – a condition that arises when a mobile phone has access to an alternative network, but cannot access the network it is tethered to. Under a national roaming agreement, all ‘time on emergency calls only’ would therefore become time when the user did have a mobile connection. Therefore, by removing these times from our overall ‘no signal’ metric, we are able to derive the actual impact of a national roaming agreement on users in the UK.

There are two further notes that need to be made about these findings in order to put them in proper context:

1) National roaming would mean that absolute coverage for all networks was the same. However, the experienced coverage as reported by our metric, would still be slightly different – as the geographic (or demographic – cheaper phones get worse signal) arrangement of subscribers is different for each network. This can be demonstrated by a simple example – If a network has a reputation for poor coverage then consumers in rural areas may be put off from subscribing, meaning that the users that do subscribe are predominantly urban and therefore experience low ‘time on no network’ (because cities are generally well covered). Vodafone and 3 have a slightly higher current ‘time on no network’ but this may simply reflect the fact that they have a good reputation for rural coverage and therefore a higher proportion of rural users – who may not necessarily be served any better by any other network. ‘Time on no network’ represents coverage as it is experienced by its users, so one network having a higher ‘time on no network’ does not necessarily mean that their actual geographic coverage is any smaller than their competitors but may simply reflect selection bias. Our panel of 40,000 users is more than enough for us to be confident in the representativeness of our data.

2) National roaming would not necessarily be a good thing. If national roaming truly did ‘eliminate blackspots’ then it would be a good thing for consumers. However, since there will still be significant coverage holes in a post-agreement world, national roaming might end up reducing the incentives for operators to ever support these remaining areas. Increasingly, independent regulators (such as ourselves) are making coverage data publicly accessible, meaning that for the first time consumers are able to access accurate network information on which to base their purchasing decisions. As this information becomes more diffuse the market itself becomes more efficient, forcing networks increasingly to differentiate according to their network provision (speed and coverage) rather than simply price or handset availability. If consumers have to assume all networks offer the same service (because there is no way to verify if they do or don’t) then national roaming would make sense as it would fit the market to consumers’ expectations – helping them to make better decisions according to the few variables they can easily distinguish between. With better coverage information becoming more easily available, national roaming might end up limiting expansions that the networks themselves would make in order to appeal to different segments of a better-informed market.

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StormTag fully funded

After just two days on Kickstarter, StormTag is fully funded with over $19k committed from 507 backers. But there’s still time to pre-order the key-ring weather station from $20 and boost the sensors you can use with WeatherSignal


The basic StormTag has a pressure and temperature sensors and Bluetooth LE radio. It sends data to your smartphone – WeatherSignal will be providing the initial app. To WeatherSignal the StormTag will appear functionally as extra device sensors, though they will update less frequently as we want the battery life to measured in years. Texas Instruments have shown that a year long battery life can be achieved with Bluetooth LE transmission every second, so we should be able to get the data updating faster than every minute.

On top of the pressure and temperature sensors, StormTag+ is rocking a UV meter and a humidity sensor (hygrometer) and has 10 days data storage capacity. This means you can leave your StormTag+ somewhere, come back days later and pick up all the data. We’re hoping this will have many applications: agricultural monitoring, studying the urban heat island, optimising your central heating and A/C system. We’re hopeful that this low price and the simplicity of the product (no buttons, no charging) will help put this in places where climate data sources are most lacking.

Get them on KickStarter.

Comparison of StormTag and StormTag+

Pressure Temp. Humid. Light Data Storage Connection Size Price
StormTag Bluetooth LE Tiny $20
StormTag+ 10 days Bluetooth LE Tiny $35
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A $20 Weather Station

At WeatherSignal we turn phones into weather stations. The WeatherSignal app takes readings of device sensors such as light, pressure, temperature and humidity from devices and uses these to create crowd-sourced weather maps. But there’s a problem, we’re limited to the sensors on each device. This is changing.

We’ve teamed up with StormTag, who’re building incredibly low cost, low power, waterproof temperature/pressure sensors that communicate via Bluetooth LE. We’ll be incorporating StormTag compatibility into WeatherSignal, we’re also committing to building an iOS version of WeatherSignal to support StormTag. We’ll be working closely with the makers to ensure good battery life on device and sensor and a smooth experience.

At the time of writing, after 6 hours of being live this project is 1/3 funded with $5k committed. Thanks for your support!

StormTag means that everyone with an Android or iOS device will be able to monitor temperature and pressure. These are key weather variables – pressure in particular plays the key role in determining weather flows, and in predicting and monitoring extreme weather events. We believe crowdsourcing this data will provide a dataset that far exceeds the resolution of professional weather stations.

Support the StormTag on Kickstarter and get it for $20

Following feedback form early backers and discussions with the engineers, Jon has decided to offer a StormTag+ for $35, the extra $15 allows the addition of:

  • Up to 10 days data logging. Weather data is stored in onboard memory when your phone or tablet is not connected to StormTag+.
  • Humidity Sensor: to provide more accurate forecasting and more complete data collection.

  • UV sensor: StormTag+ will now know if it is outside and provide even more valuable data.

The current state of temperature and pressure sensors
On Android our own research (based on millions of phones and tablets using OpenSignal) indicates that 74% of phones do not have a pressure meter. On iOS not a single device has a pressure sensor, although there are rumours the iPhone 6 may come with one. This means only a small proportion of smartphone users can currently contribute to our weather maps.

Temperature sensors are even less common, only about 1/10 devices currently have one (the Galaxy S4, Moto X and Galaxy Note III being the market leaders). However it’s quite likely this percentage will decrease. Unlike its predecessor the Galaxy S5 does not have a temperature sensor, the Galaxy Note 4 will probably also lack a temperature sensor. The next generation of leading Samsung devices do not have temperature sensors.

The StormTag is not the first project to enhance smartphones with external sensors, Robocat raised over $300,000 to provide a thermometer add on, Thermodo. Since then other projects have added wind and (most crucially) pressure sensors. But we think the StormTag can reach a far larger audience.

StormTag Features

  • Pressure and temperature sensors powered by a button cell (anticipated battery life in years)
  • StormTag+: humidity and UV sensors also included
  • Lowest price point of any sensor add-on with these capabilities
  • Bluetooth LE means it can monitor the weather passively, unlike other sensors that plug in via the headphone jack
  • The fact that it is waterproof and can be worn away from the device (rather than attached it) mean the temperature readings are more reliable
  • Using the headphone jack to collect data, can be problematic – it typically requires the device providing sufficient power through the jack
  • StormTag+: 10 days data logging – leave the StormTag+ outdoors, in your baot, in a Stevenson Screen – when you’re back you’ll be able to pick up the data with your device.

It’s important to note StormTag will only work with Bluetooth LE devices – this includes all of the iPhone 5 range and most new high end Android devices (HTC One, Nexus 5, S5) along with a lot of cheaper ones. We’re expecting to see the number of devices with this technology trend strongly upwards as iBeacons and other Bluetooth beacons gain ground.

If you love sensors, you’ll know about some of the other players in the market already, here’s a rundown:

Pressure Temp. Humid. Light Gas Wind Connection Size Price
StormTag Bluetooth LE Tiny $20
StormTag+ Bluetooth LE Tiny $35
SensorDrone Bluetooth LE Small $200
Node Kore with Clima module Headphone jack Medium $225
Thermodo Headphone jack Tiny $30
Shaka Weather Station Headphone jack Medium $100
Vaavud Headphone jack* Medium $60
Weatherflow Windmeter Headphone jack Medium $35

The Vaavud uses the headphone jack as an axis to rotate about, but does not communicate via the headphone jack (it uses periodic distortion of the magnetic field around the phone caused by its rotating magnets)

If you’ve read through all this, you should really back the project on Kickstarter and download the WeatherSignal Android app.

Here’s the KickStarter video:

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Mobile: The Measure of All Things (Big Data Week talk)

These are the slides from a talk I gave at Big Data Week London 2014.

We carry take our mobiles with us wherever we go, we keep them fuelled with energy and, typically, there’s no other object we own that is so sensitive to our surroundings.

This makes mobiles ideal for capturing a rich dataset about human activities and the man-made & natural environment around them. In fact mobiles are far more capable than humans as measurement tools – or sensors.

Man vs Mobile sensors

  • Mobiles can sense things we can’t – like magnetism & atmospheric pressure.
  • Mobile sensors can provide quantified and accurate readings (for example “it’s 22 degrees Centigrade”) vs only qualitative ones (“It’s quite warm”).
  • Mobile sensors can exceed human sensors in terms of the range they cover – for example the microphones on devices can pick up sounds invisible to human ears – for example the New Forest Cicada.
  • Mobiles are better at regularly reading and storing information (logging), humans find this boring.

Mobiles are getting more plentiful, being equipped with more sensor hardware, and that hardware is operating at a new level of efficiency. Taken together, this means mobile sensors could become the predominant datasource of the 21st century.

Sensors such as the gas sensor that Sensirion has developed for mobile, mean that mobiles are catching up in the few places where humans have better sensory capabilities. Co-processing or sensor batching, whereby sensors do not need to run on the main system chip, means that taking and saving sensor readings is becoming 1000* more efficient.

At OpenSignal and WeatherSignal we’re exploring the ways mobile sensors can be aggregated into sensor networks, by creating engaging apps and communities of contributors.

Our main aim is to create independent coverage maps and otherwise provide an impartial and data-backed view of how mobile networks perform. In the talk I refer to three different, and surprising, ways the data can be used. We’ve written about two of these elsewhere: how phone batteries measure the weather, how WiFis are used to express political sentiment.

The sensors in phones constitute the most powerful scientific apparatus in the world. Let’s get measuring.

My thanks to: Stewart Townsend, Ande Gregson and Ben Lorica for organising and inviting me along.

EDIT: In case you’re worrying that James sounds like he basically just views humans as inefficient sensors, well… you’d be right, as the below screenshot demonstrates. -SJ  

can a sensor love

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UK Roads & Rails

Today we published a report into mobile coverage on UK Roads and Railways,  taking a look at how well served the transport infrastructure of the UK is by mobile connectivity. This is an area that the UK regulator, OfCom, has emphasised as important for quite some time but so far haven’t been able to properly report on because of the limitations of traditional testing methods – especially when it comes to measuring mobile coverage in trains, which themselves have an impact on mobile signal.

Mobile coverage on roads is increasingly important for the success of connected cars (and, longer term, the future of the self-driving car) as these depend on having constant internet access to function properly, so mobile coverage on roads is about more than just being able to stream spotify. For trains, mobile coverage is important because it enables remote working, helping commuters become more productive and lessening the impact of travelling between offices. As the UK spends on improving its rail networks (HS2 and Crossrail being the big examples) it is important that mobile infrastructure can keep up to ensure these give the biggest possible boost to the UK economy.

And now for the overall stats: The average user on a UK motorway has 3G/4G coverage 76% of the time, 67% of the time on A-roads and 72% of the time on UK railways. Click through to check out the routes you use most often, and to see more data on specific 4G performance. All of the data in this report is crowdsourced from approximately 40,000 UK OpenSignal users, to contribute download the app from the header above!

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Become an OpenSignal iOS Beta Tester

The OpenSignal iPhone app has now been out for over a year – so we feel it’s time for a big update. If you’re an OpenSignal iPhone user, and want to be among the first to try out the new update, then we’d love for you to sign up for our Beta Test program. Just sign up through this form and we’ll send you all the instructions you need to get the brand new OpenSignal on your phone. One of the most exciting new features we’re introducing is network comparison, we’ll show you how your network has worked for you in the places you’ve been, and compare it to the others available – so you can definitely know which network will work best for you, based on the places you actually spend time.

The new version is enormously different to the last one, both in terms of looks and functionality – and we really hope our Beta testers will be able to play a big role in shaping how the app works, to ensure that we’re able to offer the best possible tool for helping people to improve their connection. In order to get you even more excited – here are the three biggest changes to the OpenSignal app that you (hopefully) know and love:

1)   Completely overhauled UI – it’s iOS7-friendly, flat and beautiful. Lots of blue and white, like it was inspired by the ocean. Sharing your speedtests/coverage stats is a lot more intuitive – making it easier to complain about your network/show off your fast Wi-Fi speeds.

2)   Background data collection– this allows you to contribute much more information to our coverage maps, making our iOS users a much more effective part of the biggest signal crowdsourcing network in the world. By using the OpenSignal app you are helping to make coverage information available for everyone, meaning that carriers can no longer hide behind inaccurate coverage maps – and everyone can access accurate coverage information before they buy a phone or switch networks. As ever, all background (and foreground) data sharing can easily be turned off in the settings by flicking a single switch.

3)   Bigger and Better stats – one of the really exciting new features we can bring you through background data collection is recommending you networks based on where you’ve been. The app looks at your connection over time and is able to compare your personal coverage with other networks (based on our extensive coverage database, built up over time from over 7 million OpenSignal users).  You never again need to say ‘will my connection be better on another network?’ the answer will be right there in your phone, written in white and blue in the OpenSignal app.

If that sounds good to you then please sign up for the OpenSignal Beta Tester Program – give us feedback, play with the app, try and break it, let us know what you like and don’t like. We’d love to hear from you – keeping our community involved is really important to us so sign up, download and get in touch!

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Help Needed: Mapping LTE Bandwidth

There are multiple factors that influence the data speed you experience: the device you use, the network operator, the time of day, the signal quality where you are. We’re building models of how these factors come together, we’ll be publishing our results and it’s our hope that they will guide the industry on how best to improve user experience.

We’re focussing on LTE currently because there are a lot of signal quality variables accessible. But, one important factor is missing from our model.

The LTE bandwidth is the quantity of spectrum over which the device sends information. There should be a roughly linear relationship between bandwidth and speeds, though it will also depend on the band used (which gives the area of spectrum being used – the frequency).

LTE bandwidth and band are not available through Android APIs. Some devices have have unpublished APIs which do reveal it, these devices are relatively common in South Korea and Hong Kong where we have a good picture of the bandwidths.

We need you help
We generally don’t ask for any help beyond downloading the app, but we’re stuck on this one. We want to run our model on more countries – the US in particular. But we don’t know what bandwidths are being used in each city.

The good news is, many phones are able to see what bandwidth is available. You just need to enter the service menu or field test mode, on Samsung Galaxy devices (e.g. Galaxy S4) just open the dialler and type:


This should open up a page of stats on your device:


See below for what to do if *#0011# does nothing

Here you can read the LTE stats easily. The Band is 7 (around 2600 MHz), and the LTE Bandwidth for download (LTE DL BW) is 15 MHz. Actually the Earfcn_dl gives a more precise reading of the band, 2825, so if this available use this.

If that works fill out this form and your information will be automatically mapped:

All the information is public, and responses are mapped immediately below – you will probably need to refresh this page before your data becomes visible. If it doesn’t appear after that there may be a problem geocoding please email me James (@ with your observation and we’ll get it up.

Map of LTE bandwidth. Click on a dot to see the observation. Get the raw data here.

Apart from improving our model, this map will give a great indication of how operators are investing in infrastructure. For example T-Mobile stated in Q4 2013 that it would have brought 20+20 LTE (i.e. 20 MHz downlink and 20 MHz uplink) to 90% of the top 25 US markets by the end of 2014 – that’s 24 cities. Readings from T-Mobile users shed light on how that roll out is doing.

Sprint’s Spark network – making use of band 26 (800MHz) is also one to watch.

If *#0011# doesn’t work
*#0011# won’t work on all devices. You can try:

However, we’ve tried these on a number of phones, and even when they do return signal and tower information we have not found them to return the bandwidth.

If you find other codes that do work, get in touch.

Posted in Help Needed!, Open Signal Maps community, Understanding signal | Leave a comment

The OpenSignal Walk

Every afternoon we take a company walk. There’s no set time, no pattern for its occurrence – someone just initiates it when they feel they’ve had enough of looking at a screen for an afternoon. It usually begins with a stretch of the legs or arms, a surreptitious glance across the table, a half nod. Then someone takes off their headphones, pushes their head above the parapet of congenial work-silence, and asks the single question:


And that’s it – headphones are out, and concentrated stillness (though often hiding a scurrilous amount of gossiping going on over Slack) is replaced by a communal unfurling. We wander out, chatting about whatever, and stroll through Clerkenwell, usually without any particular destination in mind. We had a phase of going to look at one of the many nearby churches, including numerous repeat visits to St. Ethelreda’s Chapel – distinguished by a particularly exciting crypt. Though since the onset of spring we’ve tended to direct our walks to maximise exposure to sunlight – although that’s less of a problem when you’ve spent the morning working on the White Bear Yard roof terrace.

st ethelreda's

St. Ethelreda’s, Ely Place

So how did this tradition come about? In the best standards of all tradition, repetition has utterly obscured origin – but it serves as a constant reminder that there are more important things than being tied to a keyboard all day. An acknowledgement that if the sun is shining then a stroll and an ice-cream will only improve everyone’s mood and concentration, rather than break it.  There is always a lot of talk about ‘company culture’ in the start-up world, though this often tends towards the promotion of individualism above all else (Google’s 20% time, not tracking holidays, working from home). While we also love this relaxed laissez-faire approach – working from home is always fine and we all get to work around mid-morning – we view the walk as symbolic of the collaborative environment we want OpenSignal to be.

The ‘company culture’ (an admittedly horrible phrase that unapologetically wears the taint of middle-management doublethink) we want is one where everyone is involved and intellectually interested in every aspect of the innovative work we do (mainly in the fields of crowdsourcing, sensor networks and big data), from both a technical and theoretical perspective. The walk, a moving coterie of people having the physical and intellectual freedom to unwind, think and discuss, exactly sums up how we want OpenSignal to be.


Joe and I get overexcited on a recent walk

Recently, especially, walking has been held up as a panacea to the ills of modernity, a rare opportunity to stimulate both our bodies and minds in one move – like some kind of historically-inspired ambulatory yoga. The best thing about a walk, in many ways, is the pedestrian exposure to the element of change – every walk is different, in part because the environment in which it is embedded shifts in ways that range from the dramatic to the almost-imperceptible. That is the joy of the walk, the routes are familiar enough to emphasise even subtle change and every time we talk about something different, reminding us that it is the human geography that matters more than the physical.

Walks keep us healthy, curious and calm – and above all have an interesting factual and literary history. Many of Jane Austen’s most important moments of crisis/narrative development occur during walks (Louisa Falling from the Cobb in Persuasion, Harriet being rescued by Frank Churchill in Emma) – showcasing the walk as a conduit for change and excitement. On the other side of the coin we have Immanuel Kant, famous for his daily contemplative walk around Konigsberg – interrupted only once, by his inability to put down Rousseau’s Emile.  Occasionally we also get too distracted by what we’re working on to go for a walk – but that is rare, because, almost no matter what you’re doing, it’ll prove to be less important than pausing, stretching your legs in the sun and arguing about what defines a sensor network. After all, if it was good enough for Kant, it’s probably good enough to be a universal maxim.

If you like sound of our attitude to walking (and since you’ve persevered to the end of this blog post) you might well be a great fit at OpenSignal – come and join us!

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