Radius

Privacy

Last updated 27 September 2026

Radius has no server and no user accounts. There is nothing to sign up for and nothing to log in to. Most of what follows is a description of things the app deliberately does not do.

What the app collects about you

Nothing. No analytics, no crash reporting, no advertising identifiers, no tracking of any kind. There is no backend to send anything to.

What stays on your phone

• A key created on the device the first time you open the app. It never leaves the phone. Deleting the app or clearing its data destroys it permanently, and it cannot be recovered.
• The bounties and claims your phone has heard about, cached so the app works offline.
• Your appearance preference.

What other phones see

When you post a bounty it is broadcast over Bluetooth to phones nearby and relayed onward by phones in between. It carries the title, the amount, the expiry, and a short label derived from your key. Claims and private messages are end-to-end encrypted and readable only by the two people involved.

Location

If you allow it, the app takes a single position fix when you post a bounty and rounds it to a coarse grid cell, roughly a few kilometres across, so people in the same area can find the listing when there is internet. The precise position never leaves the phone. Declining costs you nothing except that listing's reach.

When there is internet

Radius can relay the same encrypted messages through public Nostr relays so two phones that met over Bluetooth can still reach each other later. Relay operators see encrypted payloads and the public key they are addressed to. They cannot read the contents. Bluetooth is always tried first, and with no internet the app works exactly as it does with it, minus that reach.

Bluetooth

Bluetooth is used only to find other phones running Radius and to pass bounties between them. It is never used to determine your location, and the Android permission is declared with neverForLocation to say so.

The waitlist on this website

If you give your email on the front page it is stored by the form provider and used once, to tell you the app has been released. It is not added to any list, not shared, and not sold. Ask and it will be deleted.

Children

Radius is not directed at children under 13.

Contact

Questions about any of this, or a deletion request, go to aaa.software.dev@gmail.com.