Topper.com would attract any student from any background because of its interactive web page. Any student would assume it to be a good website apparantly.
But trust me it is not what it looks like. I saw some sample which they provide free of cost . There I could not sense abything wrong but as I used my friends account who paid for it and enrolled in it, I saw much drawbacks.
Firstly I would like to tell that what they promise you to provide 2 lakh questions is all false. The may be providing that much amount of questions but as you solve more you would find that same questions are being repeated after every 10 to 15 questions.
If it was a totally free website i’d have loved it but since the are being paid to maintain the website it is not worth it.
And also you can clear your doubts by viewing free youtube video lectures . So you need not use it to clear yiur concepts.