I launched in-app purchases for Chips of Fury on October 4th. Just crossed 500$ in revenue yesterday :)
This has been a soft launch to test the waters on pricing and also get some user feedback on the gameplay itself. The pricing is simple - 2$ one time for a single game in "Poker Mode" or 15$ for an unlimited games license. I don't feel I've built enough value to be able to charge a recurring subscription fee yet.
I am working on a slick redesign of the app to make it look like it is worth paying for :)
PS. If someone here plays poker and wants to do a beta test with the new UI, please let me know.