Chicktionary
Chicktionary is essentially TextTwist with chickens. For the uninitiated, TextTwist is a popular word game that was created by GameHouse and runs in Java.
As mentioned, Chicktionary is similar to TextTwist in that you have to come up with words using a provided set of letters. The only difference with this one is that you get clucking chickens who "hatch" the letters to form the words.
Created by Blockdot. Inc, the game used to be offered for $1.99 when it first came out but currently it's being offered for free on the App Store. If you're up for some fun and maybe testing your vocabulary, give the game a go.