Tether: Encrypted File Vault

KB Interactive Systems

In-app purchases

About this app

Tether is a personal encrypted vault that lives entirely on your device. Every file you add is protected with AES-256 encryption before it ever touches storage, and nothing is ever uploaded anywhere. No cloud, no account, no sign-in.

100% OFFLINE
Tether has no server. It doesn't sync, doesn't phone home, and doesn't need an internet connection to work. Your files stay exactly where you put them: inside your device's encrypted vault.

ONE VAULT KEY, NO RECOVERY
A single Vault Key encrypts everything you add. It's derived on your device and never stored anywhere else. If you lose it, there is no reset link and no support ticket that can help. That's the trade-off for a vault nobody but you can open, not even Tether.

BUILT-IN VIEWERS, NOT JUST STORAGE
Open what you import right inside the app, decrypted only in memory:
- Photos, with a proper gallery, pinch to zoom, and swipe between images
- Video and audio, with full playback controls
- Notes, in a distraction-free text editor
- Any other file type, safely stored and organised into folders

APP LOCK
A separate PIN, password, or fingerprint gate protects the app itself, independent from your Vault Key, so opening Tether on a shared or borrowed device stays private too.

SHARE BETWEEN YOUR OWN DEVICES
Files encrypted by Tether can only ever be decrypted by Tether. Extract an encrypted copy from any file's menu, move it however you like (email, USB, your own cloud storage), and import it into Tether on another device. Files you exported with your own Vault Key unlock in one tap on a device that shares it; anything else asks for the password it was protected with.

FREE, WITH AN OPTIONAL UPGRADE
Tether is free to use with a 50MB vault. A one-time Pro upgrade removes that limit entirely, bounded only by your device's own storage. No subscriptions, no ads, no tracking.

What’s new

Tether 1.0.9

First public release.

- Fixed the text editor jumping to the bottom while typing anywhere in a document
- Fixed cross-device Vault Key unlock failing even with the correct password
- Fixed the on-screen keyboard covering the password field when importing a shared file