Luftwaffles

More stable, yes.

Better designed? I wouldn't say so yet. It has a few problems.

My main annoyance is that it doesn't recognize the return button on physical keyboard phones as "send."

Also, it doesn't convert url's to links and there seems to be no way to clear users from the "recent chats" list.

And I wish the default action when touching a contact was "start chat." Profile should be a long press or something.

Clear your chat history with them.