There are quite a few free graphic resources available for games.
Unfortunately the quality varies greatly, and if you do try and go the free graphics route you’ll probably wind up doing a lot of digging to find images that look good together. All this takes time, and could leave you wondering why you didn’t just find an artist in the first place.
I found some great looking free game graphics sets made to suit iOS devices so you won’t have to do any tinkering (unless you want to). So if you are looking to put together some graphics for a tutorial, or demonstration or even your own games these are fantastic. What I really like about these resources is that you get a complete set.
The graphics resources are provided by Vicki Wenderlich and can be found here:
Free Game Art: Mole Whack
Free Game Art: Cat Jump Pack
Free Game Art: Space Flier
Free Art: Four Spaceships
Free Game Art: Monkey Platformer
Free Game Art: Squirrel Attack – Catapult Game
They are licensed under the Creative Commons Attribution License so you just need to provide some credit somewhere in your app. You can find details under any of the links.
Extremely useful if you want to get something out their fast!