I’ve degoogled Signal Messenger’s website build so it can be compiled and runs without any Google Play Services / Firebase code, and is completely open source.
Patches are available on my Github - look for the most recent branch with -FOSS in its name. I’m not distributing builds as I’m aware of the historical issues between F-Droid and Signal; this isn’t an inclusion request, on that note. Also, maps and automatic facial recognition don’t work; there’s a separate patch for OSM support which the Signal developers were not keen on merging. You will simply have to survive without Google’s binary ML-Kit facial recognition for now .
I’ve been discussing it on the Signal User Community forums, and have filed a pull request, neither of which have generated a response from the Signal developers in the last two months. (Notably recent changes to Signal mean that my pull request breaks the Play release build, but that can likely be addressed if they ever decide to merge it).
So, I figured I would post it here in case anyone is interested in building it; check the Dockerfile in Signal’s source for build instructions. Thanks to Axet’s android-firebase-fake library which I’ve lightly extended to stub out the Firebase dependencies, alongside my own GMS stub implementation – potentially these could be leveraged to degoogle more apps e.g. the new Firefox?