There are so many apps available but my favourites are Grade Up, Test Book, Prep Guru, Wifi Study, Adda 24x7, Ved Academy, Gyan Choupal, Pinnacle, KD Campus, Smart Edukings, Talent Sprint, Prep Door and Mahendra's quiz
I would like to suggest you Smartkeeda for Quizzes and Testzone for mock test. Once you start using you will start loving it because their content part is so amazing and At last Take a test and you will get to know the difference by yourself.