The secure voice app is ZRTP (they are just using an existing open source ZRTP library). The ZRTP protocol is now an RFC:
http://tools.ietf.org/html/rfc6189
The secure chat protocol they're using is something they developed and haven't yet published. It sounds as if it's similar to OTR, though. TextSecure (an encrypted SMS app I work on) uses a version of OTR adapted to the mobile environment, which is documented here:
The secure chat protocol they're using is something they developed and haven't yet published. It sounds as if it's similar to OTR, though. TextSecure (an encrypted SMS app I work on) uses a version of OTR adapted to the mobile environment, which is documented here:
https://github.com/WhisperSystems/TextSecure/wiki/Protocol