This app is developed by the top educators of India and has the best team of faculties in India( NK GUPTA SIR, PRATEEK SIR & SARANSH SIR, ARPIT MAHESWARI SIR) , all are iitians and 2 of them are under 50 ranks( 41 and 2) .
Also now the app is free for all during lock down. Go and download. It has everything needed for the preparation.
Prateek sir is my favorite teacher.