YouTube has a number of videos to watch on installation (but I don't trust unknown Repos so I installed manually). One such video is here.
Remember, the latest iKeyEx is considered BETA so be very careful. All I can say is that I'm using it and it works. iKeyEx is a Mobile Substrate add-on (otherwise, I wouldn't have installed it in the first place as I'm using/hoping Mobile Substrate's safe-guards protects the phone in case of crash). When in doubt, research other success/fail stories and understand before installing.