Nothing fancy, just a nice 100px grid, with lighter 10px divisions. Added a little lighting, and some texture, and that's about it. Similar to what I'm using on my own phone at the moment. Just figured I'd share since it's been a little while. It does size down decently, but obviously will be the sharpest at the full 2560x1600 downloaded size.
It is going to be a paid app but I'm afraid I'm extremely tight on budgets... I'd be more than willing to give you credit and link you're page on DA.
Mind if I use this for an iPhone app I'm making?
If it's just a fun app go for it. If you're looking to make some money at it send me a message and we'll make it work.