Oxford Dictionary for iPod/iPhone Touch
One of the first dictionaries I remember getting as a child and later using as a young student was the Oxford English Dictionary, which was at the time THE definitive English Dictionary. As the net has become progressively important though ,it has been somewhat superseded by relative newcomers such as Google Dictionary and Wikipedia Dictionary. However with a pedigree of over 100 years of compiling words this app has got legitimacy written all over it.
Download now for a definitive thesaurus and word compendium with all the authority of a true intellectual giant.
Before we move on lets give something back to those hanging with friends: Words with Q and Z: Quince; quintuplet;queen;quarry;quaff;quibble; zoroaster ;zoroastrianism;zoo;zeedonk;zenith
Not an app but a useful site I found on the net for quick and easy access to scrabble type words: enter your words; prefixes and suffixes and voila!
Go Street with: iPhone Urban Dictionary
When you tire of being civilized and playing iPhone word games you can go all street on yo bros and flip them out with the urban dictionary. You probably won't get much Words with Friends mileage out of it but it's fun and might even help you to understand any teenagers about.