Phosphor Games’ Horn is a pretty great adventure that most iOS gamers would do well to experience, and it’s currently free.
If for some odd reason you haven’t helped the young apprentice save his village (and the rest of the world, really), well there’s no time like the present is there? And if that’s not enough, there’s also the challenge modes that will keep you busy well after the main story has concluded.
For the time being, you can grab Horn off the App Store for free. I’d suggest you avoid dawdling.