i have knowledge about : Android SDK with Eclipse,OOPs, Core Java, XML,Web Services(JSON), SQLite databases, Google Maps API, Google Play Store, push notifications (GCM), social media integration(Face-book(Login), Google plus(Login)),Services, protocol(http, ftp),Audio, Video, Animation,Activity, Fragment, Adapter (Base Adapter and Array Adapter), View (ListView, GridView), Manager(Location Manager, Telephony Manager, Notification Manager,sms manager), Camera, Spinner, DataPicker, TimePicker, checkbox, radio box, edittext, textview, contacts, Alarms,Calender,Menu,Action bar,Shared preferences, Sensor (for compass).