qlib JEE-Advanced application allows the students to prepare for the Joint Entrance Exams(Advanced) by attempting free mockup tests for JEE-Advanced using previous year question papers for JEE-Advanced Examinations.

Students can also learn the solutions in the "Tutor Mode" where the student will be able to study the answer of each and ever question from the previous year questions of JEE-Advanced exams.

The student, if required, will also be able to download the PDF versions of the previous year papers for JEE-Advanced exams to print and use it offline.

qlib JEE-Advanced has question papers and solutions for the all the exams from the year 2014 till today and will be updated as and when the new exam happens.

The qlib JEE-Advanced application is free and student can appear for online Mock JEE-Advanced tests using the previous year papers and hence prepare.
This app has "Solutions" too.
So that is why i am interested. Also if you see in their menu, they have lots of other exams covered too. So if we can crack this one, then hopefully we will be able to crack them all.