Spiral Quarterly Update Covering LDK, BDK, Bitcoin Design, and More

Krux is open-source firmware for building DIY Bitcoin signing devices using off-the-shelf parts. It runs on Kendryte K210 devices like the M5StickV and Maix Amigo, turning them into airgapped devices that can sign transactions for singlesig and multisig wallets.

Liana is a Bitcoin wallet that uses miniscript output descriptors, with extensive use of relative timelocks (OP_CSV). It features a timelocked recovery path for all your coins and can be used for inheritance, decaying multisigs and generally safer backups. Available on Windows, Mac and Linux.

ZEUS is a mobile Bitcoin and Lightning wallet, and remote node manager for LND and Core Lightning. Available on Android and iOS.

Bitcoin Keeper is an open source, mobile multisig bitcoin wallet with inheritance features. Keeper Desktop is a companion desktop app that allows you to securely use hardware wallets with the Bitcoin Keeper mobile app.