[ForHackernews]

I hope this distinction is called out effectively in the UI. It would be a real disaster if people thought they were sending secure SMS, when actually they were using plaintext, or got confused between which are SMS messages and which are TextSecure messages.

[jhgg]

It is. secure messages are blue (and the send button has a lock on it), text messages are green. Similar to how iOS does iMessage/SMS messages.