Silkbound

A private app for two. Encrypted on the phone, not on the server.

Download

Download the APK

Checking the version…

Android 8.0 and newer. This is not from Google Play — after the download your phone will ask for permission to install from this app. Later versions the app offers you by itself.

Languages

English, German, Spanish and French. The app asks on its very first screen and you can change it later in Settings — it applies to the app only, not to the whole phone.

How to pair

  1. Install the app on both phones.
  2. On the first one: with an invitation, tap Open in the app above — otherwise pick This is my phone and enter the code you were given.
  3. The first phone then shows a numeric pairing code.
  4. On the second one pick This is my partner’s phone and type that code.

The code is short-lived and works once. When it expires, create a new one on the first phone.

What the server sees

None of the content. Tasks, notes, the calendar and polls are encrypted on the phone with a key the server never receives. What sits on the server is an encrypted blob and two technical values the access rules need.

In practice: if someone got to the server, there would be nothing to read. It also means a lost key cannot be recovered — so write down the recovery key the app shows you at first start.