Terms governing your use of Trail Signal — Last updated: 29 July 2026
1. Agreement to Terms
By accessing or using Trail Signal (the website at trailsignal.uk and the Android mobile application), you agree to be bound by these Terms of Service. If you do not agree, you should not use the service.
Trail Signal is provided by Usefulish Ltd, a company registered in England and Wales (company number 17360947), registered office 71-75 Shelton Street, Covent Garden, London, WC2H 9JQ. These terms are governed by English law.
You must be at least 16 to use Trail Signal.
2. What Trail Signal Does
Trail Signal is a mapping and route-planning tool designed to help hikers, runners, and walkers understand and plan around mobile phone signal coverage in the United Kingdom. Its features include (but are not limited to):
Topographic maps with contours, rights of way, and terrain
Mobile coverage layers: Ofcom predicted coverage, Ofcom drive-test measurements, community-contributed signal observations, and inferred cell tower locations
GPS track recording with live signal measurement
Signal alerts — estimates and warnings about signal loss, including predictions along a route or direction of travel
Signal reports for routes, GPX import, and offline map downloads
Features evolve over time, particularly during the beta (see Section 3); the app itself is the definitive description of what it currently does.
3. Free Beta
Trail Signal is currently in a free beta. This means:
Everything is free. No feature in the app currently costs money, and we do not collect any payment details.
Things will change. We are actively developing the app. Features may be added, changed, or removed while the beta lasts, and you may encounter bugs.
Back up what matters. We take reasonable care with your data, but beta software carries a higher-than-normal risk of bugs causing data loss. Please export important recorded tracks (for example as GPX files) rather than relying on the app as your only copy.
The beta will end. We plan to introduce a paid Premium subscription — see Section 6 for what will change, what stays free, and how much notice you will get.
Nothing in this section affects your statutory rights.
4. Data Accuracy and Limitations
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Trail Signal provides coverage information on a best-effort basis. No guarantee of accuracy is made or implied. Coverage data should be treated as indicative only and must not be relied upon for safety-critical decisions.
Signal Alerts and Predictions
Signal alerts — including warnings that signal is fading, predictions that a “dead zone” lies ahead, and estimates of where or when coverage will return — are estimates derived from modelled coverage data, your phone's measurements, and your movement. They may fail to appear, appear late, or be wrong in either direction. Do not rely on them for safety-critical decisions: do not assume you will have signal because no alert fired, and do not assume you will lose it because one did. Plan as you would without the app, and carry appropriate backup means of communication for remote terrain.
Cell Tower Locations
The cell tower locations shown in Trail Signal are inferred estimates, not verified ground-truth positions. They are compiled from publicly available datasets and computational analysis:
Ofcom Sitefinder (2012) — the most recent comprehensive UK mast survey published by Ofcom, now over a decade old. Many towers have since been relocated, upgraded, or decommissioned.
OpenCellID — a crowdsourced database where tower positions are estimated from smartphone observations. Positional accuracy varies and can be 100 metres or more from the actual tower.
Ofcom Wireless Telegraphy Register — records of licensed microwave backhaul links, which provide indirect evidence of tower presence.
We have made a best effort to validate and cross-reference these sources using terrain analysis, line-of-sight raycasting, and spatial attribution (see our full methodology). However:
The dataset contains over 114,000 sites across the UK. It is not feasible to individually verify every location on the ground.
Accurate, real-time cell tower location data is proprietary to the mobile network operators (EE, Three, O2, Vodafone) and is not publicly available. Operators treat this information as commercially sensitive and do not publish it. The datasets available to us and to the public are inherently incomplete and approximate.
Tower positions may be inaccurate by anywhere from a few metres to several hundred metres.
Some towers shown may no longer exist; some existing towers may not be shown.
Network sharing arrangements (such as MBNL between EE and Three, or CTIL between O2 and Vodafone) mean operator attribution may not always be correct.
Ofcom Predicted Coverage
The Ofcom coverage layers show predicted signal coverage as modelled by Ofcom using propagation algorithms and operator-supplied data. This is not the same as measured, real-world coverage. Actual signal availability depends on:
Weather conditions and atmospheric effects
Vegetation, buildings, and terrain not captured in the model
Your specific handset and its antenna capabilities
Network congestion and temporary outages
Time since the model was last updated by Ofcom
Community Signal Data
Community Signal observations come from other users' recorded walks. This data reflects what those users' devices measured at a particular time and place. Signal conditions change constantly, and a reading from one device on one day may not reflect what you will experience. Observations are snapped to a 50-metre grid, introducing additional positional rounding.
What This Means For You
Do not rely on Trail Signal as your sole means of determining whether you will have phone signal.
Always carry appropriate safety equipment on walks in remote areas
Do not assume you will be able to make an emergency call based on coverage shown in this app
Coverage information is provided to help you plan, not to replace proper preparation
If reliable communication is essential to your safety, consider carrying a satellite communicator or personal locator beacon (PLB)
5. Your Account
You may create an account using Google Sign-In. You are responsible for maintaining the security of your account credentials. You agree to provide accurate information and to notify us if you become aware of any unauthorised use of your account.
6. Future Pricing and Notice of Charges
During the beta, nothing in Trail Signal costs money and nothing can be purchased. When the beta ends, some features (“Premium” features) will become part of a paid subscription.
Our current plans — these prices and dates are indicative and may change before launch:
Indicative pricing: £19.99 per year or £2.99 per month
Timing: no date is committed — the beta runs until we announce its end in the app, and it may run longer than we originally plan
Our notice commitment: we will give you at least 30 days' notice in the app before any feature becomes paid or before anything could be charged. You will never be charged automatically: a subscription will only ever start if you explicitly purchase one through Google Play. Nothing you do during the free beta commits you to paying anything.
Free forever. The following will remain free after the beta ends:
The coverage map layers (Ofcom predictions, drive test, Community Signal)
Offline map downloads for your own routes
Recording your walks (GPS track recording)
Contributing signal data to the Community Signal map
Dead-zone warnings and signal alerts
7. Subscriptions (When They Launch)
This section describes how Premium subscriptions will work once they launch. It has no effect during the free beta, and we will update these terms with full subscription details before anything goes on sale.
Billing via Google Play. Subscriptions will be sold and billed through Google Play. The price shown in Google Play at the time you subscribe is the price you pay.
Renewal. Subscriptions renew automatically at the end of each billing period unless you cancel.
Cancellation. You can cancel at any time in your Google Play subscription settings. Cancelling stops future renewals; you keep Premium access until the end of the period you have already paid for.
Refunds. Refunds are handled under the Google Play refund policy. In addition, nothing in these terms removes your statutory rights under UK consumer law, including any cancellation (“cooling-off”) rights that apply to digital services.
Price changes. If subscription prices change, existing subscribers will be notified in advance through Google Play and, where required, asked to agree before the new price applies.
8. Founding Contributor Promotion
The offer: contribute at least 25 km of Community Signal data during the free beta and you will receive 12 months of Premium free when subscriptions launch.
How your contribution is measured
Your contribution is measured by our servers as the number of unique 50-metre grid cells of Community Signal data recorded from your uploads. The app shows this as “km” (each unique grid cell counts as 0.05 km). Only data actually received and accepted by our servers counts — distance figures shown on your device before upload do not. Walking where there is no signal (a dead zone) produces no signal readings, so it may not add to your total.
Conditions
Qualifying contributions must be recorded by our servers before the beta ends. We will announce the end of the beta at least 30 days in advance (see Section 6).
One reward per account. The reward is non-transferable and has no cash alternative.
You must hold an account in good standing (not suspended or terminated for breach of these terms) at the time subscriptions launch in order to receive the reward.
Deleting your account forfeits the reward. If you delete your account (or ask us to erase your data), your contribution record is permanently deleted along with everything else linked to your account — see Sections 10 and 14. We cannot restore the record or the reward afterwards, because we no longer hold anything connecting the contributions to you.
Fair play. We may withhold, adjust, or revoke the reward where we reasonably believe contribution data was falsified, spoofed, artificially generated, duplicated across accounts, or otherwise submitted in breach of these terms.
We may change or withdraw this promotion for the future, but we will not take away a reward you have already earned except in the abuse cases described above.
9. Acceptable Use
You agree not to:
Use the service for any unlawful purpose
Attempt to access other users' data or accounts
Scrape, bulk-download, or systematically extract data from the service beyond normal app usage
Reverse-engineer the application or its APIs
Upload malicious content or content that infringes the rights of others
Deliberately submit false or misleading signal data
10. Your Content
You retain ownership of any GPX routes you upload and any track recordings you create. By uploading content, you grant Trail Signal a licence to store and process it for the purpose of providing the service to you.
By contributing data to the Community Signal layer, you grant Trail Signal a perpetual, royalty-free licence to use, display, and distribute that anonymised data as part of the coverage map. Third parties cannot identify you from this data, and the identifier linking it to your account is erased when you delete your account (see our Privacy Policy for anonymisation details).
What happens if you delete your account: we erase your personal data and the identifiers that link Community Signal contributions to you (including your hashed contributor ID and any Founding Contributor record). Community Signal cells that have already been aggregated into the shared coverage map are anonymous — they contain no identity and no timestamps and cannot be linked back to you — and these anonymous map cells remain part of the map after your account is erased.
11. Third-Party Data and Attribution
Trail Signal incorporates data from third-party sources, each with their own licence terms:
Ofcom — predicted coverage data and Sitefinder records are Crown copyright, published under the Open Government Licence v3.0
OpenCellID — cell tower data licensed under CC-BY-SA 4.0
Mapzen / Nextzen — terrain elevation tiles
12. Limitation of Liability
To the fullest extent permitted by law:
Trail Signal is provided "as is" and "as available", without warranties of any kind, whether express or implied, including but not limited to warranties of accuracy, fitness for a particular purpose, or non-infringement.
We do not warrant that coverage data, cell tower locations, or signal information is accurate, complete, or current.
We shall not be liable for any direct, indirect, incidental, consequential, or special damages arising from your use of, or inability to use, the service.
We shall not be liable for any loss, injury, or harm resulting from reliance on coverage information displayed in the app.
Nothing in these terms excludes or limits liability for death or personal injury caused by negligence, fraud, or any other liability that cannot be excluded or limited under English law.
13. Service Availability
We aim to keep Trail Signal available at all times, but we do not guarantee uninterrupted access. The service may be temporarily unavailable for maintenance, updates, or due to circumstances beyond our control. We reserve the right to modify or discontinue the service at any time.
14. Termination
You may stop using Trail Signal at any time. You can delete your account and its data from within the app, or by contacting us at the address below. Deleting your account erases your personal data and contribution identifiers; already-aggregated anonymous Community Signal map cells remain part of the coverage map (see Section 10), and any Founding Contributor progress or reward is forfeited (see Section 8). We may suspend or terminate your access if you violate these terms.
15. Changes to These Terms
We may update these terms from time to time. Material changes will be communicated through the app. Continued use of the service after changes take effect constitutes your acceptance of the revised terms.
16. Governing Law
These terms are governed by the laws of England and Wales. Any disputes arising from these terms or your use of the service shall be subject to the exclusive jurisdiction of the courts of England and Wales.