I've tried doing a Facebook Instant Game Export recently. I followed the tutorials, and was able to release a test version of the game.
I was able to share it to a private test page, which worked fine using a pc browser - it appeared with a "Play Now" button. Unfortunately when I tried this from mobile FB app (from an ipad and phone), the button was not there, and it looked like there was no way to activate the game from the shared post.
Is there some way to get Instant game to be played from the Facebook mobile app?