Kev of Afterpad first reported this check out his informative report here
I noticed on the Apple store site a review of the MOGA Rebel mentioning this, now let's be clear this is not a bug of the Rebel infact it works on any MFi Controller & is a hidden feature of iOS8 for people who wish to use it as an "Easy access" to the main iOS menu.
What i've also found is it can also be used to activate "Siri" by holding the pause button down longer which can be good if you have your device hooked up to a Large screen TV and need to launch other games by using voice commands from the comfort of your sofa.
To launch a game without needing to get up from you sofa (and potentially lose your comfy spot to the cat), simply hold the pause button until Siri pops up and say "Open" (then the Name of Game).. bit lazy i know but comes in useful.
If this feature annoys you or you think it's a bug (or you don't have a cat) it can be easily turned off.
Heres how:- on your iOS device going into :
- Guided Access
- Switch OFF
NOTE: Just remember if you do keep it switched on, the pause function is disabled in games, instead it will jump out to the main ios menu.