Question: How do I access #Signal chats under #GrapheneOS ? ElementX and Matrix-Signal-Bridge?

@alexshendi simplest way is by downloading the APK:
https://signal.org/android/apk/

Molly is an alternative Signal client that supports UnifiedPush, requires you run a small server component MollySocket somewhere.
https://molly.im/
https://github.com/mollyim/mollysocket

Signal Android APK

Advanced users with special needs can download the Signal APK directly here.

Signal Messenger