9app is just a app or an site to download app for android mobile, it is just like playstore. But according to my experience I dont fund it safe for mobile phones. Whenever I try to download some app from 9 app, it used to download some type of other app which is completly useless. Also it gives a lot of ads which is difficult to cancel out . Mobile phone mostly hangs which using this app. The user interface is very difficult to work. I dont recommend any one to use it under any situation.