Dragon, Fly! Full
If you have an Android phone, this is a great time sink. They've recently opened up microtransactions, which is annoying, but you can ignore them. It's very basic gameplay, you just tap and hold to dive, and you use that to control where and how you land and how far it makes you fly. Very addictive, very fun, very frustrating.
Yeah, no iOS port. Bummer.
Well, if I recall, Dragon, Fly! is actually a clone of something on iOS.