TLS sounds about right. The protocol also provides a verification protocol (see http://waveprotocol.org/), so actions performed by any participant in a hosted conversation can always be verified by other participants in that hosted conversation, regardless of their provider. What this means for you: encryption (TLS), and your contributions can't be tampered with.

If you move a compiled app to the iPhone without running it through XCode, it just gives a giant image of an application icon when run. No doubt this will be hacked soon enough.