Happy Leaf is not yet available in the iOS App Store, but is available through Testflight. After your beta application has been seen, you will receive a Testflight invitation.
Bugs do exist, and not everything has been tested fully. If you experience issues, please contact Brandon Martin. File an issue at https://github.com/blandman/HappyLeaf/issues or reach out to the Google Group https://groups.google.com/forum/#!forum/happy-leaf-beta