Heretoo (www.heretoo.com) is a mobile social game where you find and create virtual items all around that you can use to earn points, level up, and give as gifts to your Facebook friends.
We launched into public beta tonight at Boston's Web Innovator's Group and got quite a few questions about our use of Sencha Touch, so I'll be posting some client source code soon. Generally speaking, I'd bet Heretoo is one of the largest / most complex Sencha Touch apps out in the wild, so I'd be happy to answer any questions folks have about how we did this or that.
The app is PhoneGap-packaged for the app stores, but we still keep a pure-web version around for all of you purists!
Please download it, review it, break it, and post your bugs!