How to record my phone screen while playing a game?

I'm sure there's software that you download in the app store or by connecting your phone to a computer. Another way is jailbreaking or rooting your phone which makes it easier to download screen recording software.

I don't know if this will work but there's something called a game capture I think Elgato hd is the best. You should buy it it's like $170 bucks at Amazon and it records your gameplay. So then you can put it in software like Windows movie maker or something and have a video of you playing