It is good app for the study purpose. You can get the latest material of the study. They provide the trial of this app. After that you have to pay money if you are satisfied with the content. Whenever you install this app you can get the benefit of this app. I heard about this app from the television. No of times on the TV their advertisement comes. So I also discussed with my friends regarding this app. You can also use the trial version if u satisfy then continue with the premier version. See your interest then use the premier. The content of this website is good.