Friends these app usually asks for watching videos and downloading various applications such as flipkart , amazon and a variety of applications . This is because they usually get 1$-2$ when u download any application from their app or their platform and when u download that app to get 10 -20 rs . They get usually 200-300 rs for that complete task mentioned .of which they give you only 10-15 % which is not a good deal .an in this way they use you to make money. Which is not good. So I suggest you not to go for this deal and do any otger work.