1.) MVC pattern.2.) XML, JSON parsing.3.) placing apps through google Ad and iAd (apple)4.) implement google map and other Api's.5.) radar integration.6.) all weather related data integration (like forecast )7.) talking tom like app & animation.8.) QR code scanning.9.) navigation / tab bassed application.10.) appointment schedulle like app.11.) PNs local & server.12.) ipad app .13.) bug tracking & resolving.14.) Sqlite local database.15.) Social networking Api's like Fb, Twitter, Linkedin, Weibo.16.) Searching Api's like yahoo, google, bing.