I couldn't really care about an android app that won't stake, but an in-wallet trading feature would be nice.
In-wallet trading, however, is an awesome idea. I'll bring that up with the team. Suggestions on which exchange to support are welcome.
Bittrex would be my choice, but any major exchange would do.
in wallet trading is nothing more than some API calls to bittrex, the tech/code is already easily available (think bots) and then tailor to your specs, and use Qt to add into wallet...
XST going to 20k... you know it is...