John Carey is one of my favorite photographers. It is not unusual for you to see my Mac, iPhone, or iPad graced with one of his wallpaper photos.
He just released his long-awaited (by me, at the very least) iOS 7 Parallax Pack. I know from conversing with him on twitter that he meticulously sought out the optimal resolution to give enough margin to keep the images crisp and clear while playing to the fun of the parallax effect.
In the past John has given these away for free. You can get 30 of the images for free for either iPhone or iPad. But he also has 70 more available for a humble price. You can get either an iPhone only or iPad only pack for $7 each, or a combined iPhone/iPad pack for $10.
Well, I have to say this is $10 well spent for such great art that will delight me daily.