I've submitted 5.5.0 to the App Store. Contained in it are a few bug fixes (delete vs. backspace, custom keyboard key sizes, etc.) and significant protocol update. As of 5.5.0, mosh protocol support will be available.
Because mosh uses some encryption methods (namely OCB) not used in standard ssh, this required extra paperwork and licensing. I also need a good way to report, for licensing purposes, how many people are actually using mosh. So, that being said, mosh has been made an in-app purchase for a nominal US dollar.
I'm not making a habit of charging for extra features and mosh was a particularly special case where the hardest part has been the legal issues rather than software development ones.
I'll keep everyone posted.
Feedback is always welcome. Also, if you like iSSH, please leave a review in the app store!
Dean