FROST threshold signer and Nostr event signer for Android
About this app
Keep is a FROST (Flexible Round-Optimized Schnorr Threshold Signatures) threshold signing app and dedicated Nostr event signer for Android. It lets you hold FROST key shares on your phone and sign Nostr events without any single device ever holding the full private key.
Keep implements the NIP-55 Android Signer protocol and NIP-46 remote signing, so any compatible Nostr client can request signatures directly.
Features: - FROST threshold signing (2-of-3, 3-of-5, etc.) - NIP-55 Android Signer protocol - NIP-46 remote signing (bunker service) - Import and export FROST shares via QR code or text - Multiple account support - Per-app signing permissions and policies - Biometric and PIN authentication - Hardware-backed key storage (Android Keystore) - NIP-44 encryption and decryption - SOCKS proxy support (Tor) - Encrypted backup and restore
Licensed under MIT, by PrivKey LLC.
What's New in v1.1.8
Imported from the F-Droid repository index.
- Adds first-run onboarding: guidance on FROST key shares and a sign-policy choice during setup. Also brings the app listing screenshots. No other functional changes.
Version history
Jul 12, 2026 · 26.2 MB · Android API 33–36 · code 264
Imported from the F-Droid repository index.
- Adds first-run onboarding: guidance on FROST key shares and a sign-policy choice during setup. Also brings the app listing screenshots. No other functional changes.
SHA-256 919b70a76a9b4b8750539da58b92c086752b1d04b6d580fdbf1169a4e1ff90c8
Jul 12, 2026 · 24 MB · Android API 33–36 · code 262
Imported from the F-Droid repository index.
- Adds first-run onboarding: guidance on FROST key shares and a sign-policy choice during setup. Also brings the app listing screenshots. No other functional changes.
SHA-256 7729240c2c61f6b8c80550192ae5c754eac9f5d77c0848ae9e5a6512ad909790
Jul 11, 2026 · 26.1 MB · Android API 33–36 · code 254
Imported from the F-Droid repository index.
- Restores reproducible builds: the UniFFI bindgen code, whose generated output was non-deterministic, is no longer linked into the runtime library, so libkeep_mobile.so compiles deterministically again. Also updates dependencies.
SHA-256 7c7708d164bb6c70bfe7137185264f3cdae0fe89b7e92ec5360ad88f0843cacc
Will it run on your device?
74%
- Targets newer Android builds, so legacy devices may be excluded.
- Multiple CPU architectures are covered.
- Aligned with the latest Android target SDK expectations.
Installation Guide
Open Settings on your Android device
Go to Security → Unknown sources (or Install unknown apps)
Enable "Allow from this source" for your browser or file manager
Open the downloaded APK file from your Downloads folder
Tap "Install" and wait for installation to complete
Launch the app from your home screen
Make sure to re-enable Unknown Sources restrictions after installation for security.
How to install this safely
How to verify the file you downloaded
Before you install anything, confirm the file is the one described here. On a computer, run shasum -a 256 your-download.apk (macOS or Linux) or certutil -hashfile your-download.apk SHA256 (Windows), then compare the output character-for-character with the SHA-256 on this page. If a single character differs, the file is not the build we recorded — delete it.
What the signing certificate proves
Every Android app is signed with a private key that only its developer holds. The fingerprint on this page is a hash of the matching public certificate, and it proves continuity rather than identity: it tells you a build came from whoever signed the earlier ones. Android enforces this at install time — if a package claiming to be io.privkey.keep is signed with a different key, the system will refuse to install it over your existing copy. A fingerprint that changes between releases is worth pausing on, because a repackaged app that has been modified by someone else cannot keep the original signature.
How to roll back to an earlier version
If the current release misbehaves, 1.1.8 is the last build before it. Android will not install an older version code over a newer one, so you must uninstall Keep: FROST Nostr Signer first — which clears its local data unless you have a backup. Reinstall the older APK only if its signing fingerprint matches the build you already trust, and check the API range: an older release may target an Android version your device has moved past.
Why we list sources instead of hosting everything
The official store channel is almost always the right choice: it updates automatically and carries the publisher's own distribution guarantees. A direct APK is useful when a device has no store access, when a rollout has not reached your region, or when you need a specific version — and only when the publisher has authorized that copy. APKBrowse does not list pirated, cracked, or unauthorized rebuilds of Keep: FROST Nostr Signer, and a listing is removed when the evidence for it stops holding up.
Get Keep: FROST Nostr Signer
Every source we list for io.privkey.keep is legality-reviewed. Pirated or cracked builds are never offered.
Other sources
F-Droid listing
officialF-Droid builds this app from source and signs it. This is its official listing, with older builds and full release notes.
Source code
verified publisherThe upstream repository this build is compiled from.
We check legality and signature continuity, but device behaviour still varies. Install at your own discretion.
App Information
Security Verification
We record provenance; we do not run malware scans. Verify the hash yourself before installing.
SHA-256 Hash
919b70a76a9b4b8750539da58b92c086752b1d04b6d580fdbf1169a4e1ff90c8
Signing certificate
3eb0e6f6f4e0962ebd717f84eea47428b73087b686c956633d6a9fcc4c854f50
Permissions Required
Previous Versions
The signing certificate fingerprint for this release is on record, so a build that does not match it did not come from this publisher.
Report a problem with this listing
A listing is only as good as its corrections. If a source is broken, a signature looks wrong, or this app should not be here, tell the moderation team.