Dragon, Fly! Free This little dragon can't quite fly yet so it slides up and down the hills to gather momentum and then takes off and flies through the sky for points. Fun, addictive, easy to learn.
Dragon Hunter II This game has you defensing your castle from flying dragons, earning and spending coins, repairing your castle, and collecting food. Fun and addictive - just enough different elements to be really engaging.
Dragon Rush Pro This game sends your dragon on speed runs to recover his kidnapped girlfriend. Avoid obstacles, collect items, make it to the end of each round. This game is fun and colorful.
Snappy Dragons Reminds me of a mixture of the old game Scorched Earth and Angry Birds - only with dragons.
Choice of the Dragon I was just so surprised to see a text-based choose-your-own-adventure style game that I had to put it on the list. Play old school on your phone.