I have bugged paul of tgc for a long time about 2d shaders.
But you could also use 3d planes in the background or in front of sprites.
Simply adjust sprite and 3d depth to wath you desire.
The 3d part supports shaders.
I could try to make an sample but i dont have anytime to spare, as van b and my Project takes pretty much all my spare time after work.
Not everyone knows that agk sprites can be in front and in the back of displayed 3d.
Android 2.3 , ZTE Skate , 480x800 , 800 mhz , Samsung Galaxy Y , 240x320 , 832 mhz , Sony ericson arc 480x854 , 1 ghz
Android 4.0 , Dmtech 3g 9738B , 1024x768 , 9.7 inches , 1.2 ghz