Last updated: 25 August 2026
Bandline is an offline radio-signal reference and measurement tool. This policy describes every piece of data the app touches. It is short because the app does very little with data, and specific because a vague privacy policy is worth nothing to the person reading it.
Bandline listens through your device’s microphone, and nothing it hears ever leaves your device.
Field captures. If you use the Field Harness to save a capture, a plain-text file describing the measurements — not the audio — is written to your device’s cache directory. It contains numbers, the note you typed, your app version and your device’s audio sample rate. It stays on your device unless you choose to share it using your device’s own share sheet, at which point it goes wherever you send it and this policy no longer governs it. Captures are capped at 50 files and older ones are deleted automatically; the operating system may also reclaim them at any time.
Bandline reads your device’s region setting — the country your device is configured for, not your position. There is no GPS access and no location permission is requested.
It is used for one thing: putting nearby entries first in lists, and choosing which country’s frequency allocations to show by default. It is never transmitted. Nothing is ever hidden from you because of it.
Bandline works entirely offline. The frequency database, signal reference and all analysis ship inside the app.
The one network request the app makes is a check for its own updates when it
launches. This contacts Expo’s update service (u.expo.dev) and carries no
information about you, your location, or anything you have measured or looked up.
It exists so that corrections to the app can reach you without waiting for an app
store review.
There is no analytics, no telemetry, no crash reporting to a third party, no advertising, and no tracking of any kind.
Nothing. Bandline has no account system, no login, no user identifier, and no server that holds data about you. We cannot identify you, because we hold nothing that could.
Data created on your device and kept on your device:
| what | where | why |
|---|---|---|
| Saved field captures | app cache directory | so a measurement session survives leaving the screen |
| The frequency and signal database | inside the app | offline reference |
That is the complete list.
Bandline is a technical reference tool with no social features, no user-generated content visible to others, and no data collection. It is not directed at children, and it collects nothing from anyone regardless of age.
The frequency allocation data ships inside the app and comes from public regulatory sources — among them the US NTIA Table of Frequency Allocations, the FCC, the Swiss regulator and the EU short-range device decisions. Each source, its licence and any modifications we made are listed in the app under Settings → Sources. These are one-way: we read published data, and send nothing back.
Because Bandline holds no personal data on any server, there is nothing for us to disclose, correct, export or delete on your behalf. Everything the app has is on your device, and uninstalling the app removes it.
If you shared a field capture with us, you can ask us to delete that copy; it is the only thing we could possibly hold, and only because you sent it.
If this policy changes, the “last updated” date above changes with it. A change that widened what the app collects would require a new app release, because the behaviour described here is enforced in the app’s code and configuration rather than by policy alone — the app requests exactly one permission, and its Android manifest explicitly blocks the ones it does not use.
See also: Support