Wifi study is the best app to study in these days , because it covers full syllabus of the exam that you selected and aside of this they also have a YouTube channel named Wifi study , one can also get help from there , if it is not getting in his/ her mind in app . The app gives depth information about every topic and subtopics in detail with suitable number of example. You can find wifi study app on play store and app store as well . I recommend you to use this app for your proper guidance. Thanks!