Latest readme explaining iOS 7.x support: http://phoenix-dev.com/Drop/README
My iOS 6 icon sizes were 12x20 for 1x and 20x40 for 2x
iOS 7 example sizes are:
Black_Airplane~iphone.png 12x20
Black_Airplane~iphone.png 26x40
The status bar is slightly taller when on the lock screen.
LockScreen_Airplane~iphone.png 14x24
[email protected] 28x48