The big issue with Signal at the moment, is that it doesn't work on AOSP.
You can't use it without installing closed-source Google Apps (Play Services for GCM at minimum), and means you agree to hand over your phone metadata to Google (per the OP's top-thread). Moxie has stated he is open to consider high quality PR's to add Websocket functionality. (Removing close-source binary blobs would be a prerequisite to distributing on anything other than Google Play to though, which Moxie's also said isn't on the roadmap - I assume primarily because of resources).
In the meantime, Conversations.IM has OMEMO and Vector.IM has Olm/MegOlm.
There's not a lot of good voice options. Vector.IM's just added WebRTC, which is meant to be DTLS secured. CSipSimple does ZRTP, but it hasn't been updated in a long time.
None of the apps mentioned above has been audited and scrutinised to the extent Signal has.
If you really need privacy & security, CopperheadOS is the only Android distro AFAIAA that fits the bill at the moment.
I wouldn't pin too much hope on having a high quality PR written and integrated back to Signal soon. It doesn't look like a top priority for them. OWS also like the telemetry that Play gives them for diagnostics and have stated they won't be looking at FDroid unless someone can replace that.
You can't use it without installing closed-source Google Apps (Play Services for GCM at minimum), and means you agree to hand over your phone metadata to Google (per the OP's top-thread). Moxie has stated he is open to consider high quality PR's to add Websocket functionality. (Removing close-source binary blobs would be a prerequisite to distributing on anything other than Google Play to though, which Moxie's also said isn't on the roadmap - I assume primarily because of resources).
In the meantime, Conversations.IM has OMEMO and Vector.IM has Olm/MegOlm.
There's not a lot of good voice options. Vector.IM's just added WebRTC, which is meant to be DTLS secured. CSipSimple does ZRTP, but it hasn't been updated in a long time.
None of the apps mentioned above has been audited and scrutinised to the extent Signal has.
If you really need privacy & security, CopperheadOS is the only Android distro AFAIAA that fits the bill at the moment.