Flat design is of course a trending design style right now, but the great thing with it is that you can mix it a little with skeuomorphism.
Sometimes completely flat can end up looking boring and just too shallow on touchscreen devices. Having some sort of depth just gives it that edge and can make or break the design of something like a simple button.
Aplo is a new Cydia theme that blends flat with skeuomorphism. This gorgeous theme uses very lovely flat colours but at the same time adds depth by using gradients and shadows. So instead of the icons just sitting flatly on the screen, they look like they're popping out a little and wanted to be pressed.
Aplo adds a great amount of depth to the icons without overdoing it. It doesn't just stop there though, the theme adds little touches all over the UI, changing things like pop up windows, the lockscreen and much more.
Aplo is available on Cydia right now for $1.49.