http://gamemakerblog.com/2014/06/07/gamemaker-studio-standard-is-now-completely-free/ http://www.yoyogames.com/studio/buy I know at least two popular IOS games made in GameMaker: Super Crate Box and Stealth Inc.
I picked this up in a previous giveaway and it's a really nice piece of kit. Made a very basic start on a shmup and a platformer so if I can do it, anyone can. Well worth going through the process of locking in the licence, these are never cheap packages. Cheers for the heads up Bronxsta!