Displaying the fps in game after building it

In the unity editor the stats button in the game window shows the fps and other details of the current game while playing the game. But it is not possible to view the fps after the game is builded for android and while playing it on android. So how can the fps be calculated and display it on the game in the bottom right portion while it is being played in real devices such as android phones. Also I would like to know that is there any way to display the build number also on the gui of the game using any inbuilt function or code during the debugging of my game on real devices. Or do I have to do this manually? Sorry for my stupid question. I have recently come to unity game programming and I don’t know unity completely. That’s why I asked in this forum. I have searched in google and didn’t find any solution to my problem.

@SkaredCreations Literally did Google it and this is the first result you cretin.

Why not do a google search? http://wiki.unity3d.com/index.php?title=FramesPerSecond (archive.org)