Try our most awaited Indian Public Service Preliminary Exam Helper App (UPSC Prelims).
It is free to try around 500 model questions and Exam Year 2011.
If you like, you can purchase premium versions for unlimited number of model tests from around 20,000 questions and all Exam years from 2012 (2011 is free to try)
Indian UPSC Exam Prelims Helper Application
Over 17,000 mock tests. UPSC actual year exams available from 2011
Free version has 500 mock tests and 2011 exam paper.