This is a app named by QUORA which is helpful for increase our general knowledge or well exercise for brain actaully.it is helpful for preparation of competetive exams.it has general knowlwdge ques./reasoning/biological ques./regarding to un know facts/ and etc.in it u will get a question and u have to anwser that but u can ask any question to it and u will get answer by other people whose are using it.u can also comment on their question.it is really use ful .i can download it from google play store or can direct google search .u will get results