The questions people actually ask, answered plainly.
A topographic map of the UK that shows where your phone will and won't have signal, so you can plan walks around connectivity: know before you set off where you could call for help, where to send the "running late" text, and where you're properly off-grid. The Android app adds offline maps, walk recording with live signal logging, and a warning before you walk into a known dead zone.
Yes. No ads, no card details, no trial that expires. It's a hobby project, not a startup, and a small number of users costs almost nothing to host — so it's free because it's free to run. If it ever grows to where the servers send real bills, an optional paid tier for extras will cover them; the coverage maps, offline downloads, walk recording and dead-zone warnings won't be part of it. The core stays free.
Three places, layered:
When you record your own walks, the app also shows you exactly what your phone saw on your routes.
Recording happens on your phone and stays there. Your tracks never leave the device unless you create an account and sync them, and synced tracks are visible to your account only. If you never sign in, nothing goes anywhere at all.
Sharing readings to the community map is a separate choice, and it's off by default. If you turn it on, your route is not what gets uploaded: readings are snapped to a 50-metre grid first, so what the shared map gains is "this square of hillside has weak O2" — no name and no route attached. A privacy zone setting discards anything recorded near your home or any location you choose, so your front door or your tent never becomes a data point.
Live sharing is off unless you start it, per walk, from the recording screen. Your partner gets a private link that works in any browser — no app, no account. The link contains an unguessable code, and you can add a 4-digit PIN so a forwarded link is useless without it. You can stop sharing at any moment in the app; the link dies when the walk ends and the shared trail is deleted from the server within a day. One honest note: live sharing shows your precise position by design — including near home if you start it at your front door — so start it when you set off.
Everything the app sends anywhere travels over encrypted connections (TLS — the same as your banking app). Nothing is sold, there are no ads and no third-party analytics in the app. The Google Play data safety declaration legally binds us to this: no data shared with third parties. The only thing your data is used for is a more honest coverage map.
One retired engineer who hikes — thirty years building test and measurement equipment for mobile phone networks. The app is published by Usefulish Ltd (a one-person UK company), which is registered with the ICO as a data controller (registration ZC209401 — you can look it up at ico.org.uk). The full detail is in the privacy policy.
Delete your account yourself in the app (Settings → Account → Delete account) or follow the steps on the account deletion page. That removes your account and its synced data. Tracks that never left your phone are deleted by uninstalling the app or deleting them in the app.
Not yet — the app is Android only for now. The web map works in any phone's browser, including iPhone, for checking coverage before you set off.
While recording a walk, the app compares where you're heading against known no-signal areas and warns you about 400 metres before you enter one that's at least 1.5 km across (you can change the size in Settings). It only notifies while you still have usable signal — a warning after you've lost signal wouldn't help anyone.
Record your walks, and if you're happy to, turn on community sharing — every recorded walk quietly corrects the map for the next person. During the beta, contributing 25 km of signal data earns Founding Contributor status: your first year of any future paid tier free. And if you know a hill where the map is wrong, tell us.