Is TextSecure only for SMS messages, or does it use the internet? I'm asking because of the need to send text messages abroad (at a reasonable price). Also, is there a desktop client for TextSecure? I would love something like WhatsApp -- but secure and with a desktop client.
XMPP + OTR will do what you want. I asked moxie the same question re the internet vs text, but he hasn't replied yet. As far as I'm aware it uses text for insecure stuff, and I think for initial key exchange to start the ratchet then uses the internet for secure messaging. Its quite user friendly. No desktop client, and the messages are of ephemeral so keep that in mind and see whether that's okay for your use case (it is for mine).
