Wire[1] is also an excellent option. Unlike Open Whisper Systems they wont hang you from a tree for building a third party app. Signal wont work without Gapps or Google Play Services on your Android phone and Google Chrome for desktop.

[1] https://wire.com/

Signal is pseudo-open-source but will not allow you to use it except via the closed-source google play services, so I still wouldn't have confidence in it.

Telegrams clients (and the e2e encryption) are open source. For instance: https://github.com/DrKLO/Telegram

Curious if you know why the crypto is half-baked. Has it been broken?

edit: found Signal server, I think: https://github.com/WhisperSystems/TextSecure-Server

Nice it's out there. This will help Signal live a long time.

Exactly. Not to mention if it becomes popular it will get sold to megacorp in a heartbeat.

I'll give signal another try, last time I couldn't register.

A lot of people here use twitter.

Why must things be provably sure to have any value?

No windows phone client :-(