I've considered working on TextSecure. Having a WP TextSecure would be the ideal choice. I've just been tied up in projects until now. I recently released LangBoost, and am thinking about taking on TextSecure for WP. Any other devs want to collaborate with me? There are some high level projects to work on:
1) TextSecure has a messaging hub / server that needs to be extended to support seding WP push notifications (it currently already supports iPhone and Android).
2) The app itself needs to be developed.
- Bouncy Castle seems to have most or all of the C# crypto implementations you'd need for TextSecure, that would help a lot!
Is anyone working on this? Make it public, and maybe several devs can help each other get it done!