And here the project winner of the Hackday at Lightning++ Berlin 2025 (time 1:56:56). The idea to get rid of MOBs and replace it with SATs. All powered by CASHU ecash is simply astonishing. App is available and working for those that want to replace Sigal.
Signal is an open source project. We replaced its "mobilecoin" integration with a cashu wallet, while still retaining the mobilecoin UI.
Inspiration
Signal is an open source messaging app with an embedded wallet that supports a "mobilecoin" cryptocurrency only. Arguably nobody knows it about or uses it. Therefore, we took the Cashu Development Kit foreign interface bindings for kotlin and swift and created an embedded cashu wallet that uses the same UI as the mobile coin wallet, but with the best currency in the world.
What it does
Send and receive nuts through signal. Top-up through a lightning invoice in the payments page.
How was built
With goose/cursor (LLM agentic tool), CDK bindings for kotlin/swift)