There are many steps people can take to cheat. For example:
-Photoshoping
-Slowing down the game via cpu tweeking
-Hacking the code
To protect people who are playing fair and are really trying, these are the requirements for the video: The video you must post will be a recording of you playing the game on your phone. NOT A SCREEN RECORDER, it must be recorded by Camera. For example by another phone with Sound!!
Your main purpose to avoid cheaters is great but the way to do it is so hard. I'm wondering how can I play with my 1st phone while in the same time I'm recording with my 2nd phone. Indeed I can ask for friend's help or set my 2nd phone on a phone holder but it is a bit complicated way. Now I'm start asking myself "is this your own developed app?" if it is your own app, so you should know which players play fairly and which ones play unfairly IMO.