Guys this is a classic add virus do not download. It makes you watch adds even if you closed your connection and shows adds when you use an add free application. In case if you downloaded it already, its realy easy to fix. Imma explain it step by step. (sorry for bad english)
1-Open settings in your phone.
2-Scroll down and find "applications" or "apps" and open it.
3-Find the app named "null" or " " with the white square symbol.
4-Click on the app and then you need to find delete the app on the bottom.
Thats it i hope i helped.
