would you elaborate on this?:

can't load shaders into the nexus 7.

what did you mean exactly? is your app running at all? crushing? running but not as supposed?

when i'm running it on galaxy3, android 4.1.2, i got very strange "strobe scaling" effect. i have no time to investigate it now.

could anybody else check this out? 

It seems that it crashes with 2.0b6.

It seems to come from the renderer specified P2D obviously doesn't work with shaders.

I'm definitely not an expert in processing graphics and rendering stuff, but in java mode shaders just work on P2D engine (on OPENGL as well), as in built-in shader examples.

switching to opengl the strobe effect disappeared but no blur.

This is strange. There are actually two rendering modes in p2.0b7 : P2D and P3D (opengl). When i'm using any of them explicitly, that means:
size(displayWidth, displayHeight, P2D)  or  size(displayWidth, displayHeight, P3D) i get the same flickering.

But if i not specify any render (documentation says that it should default to p2d) i get sketch running without flickering (and without shader, of course).

So my question is: what render mode is invoked when no renderer specified? And if the answer is P2D, then why declaring P2D explicitly cause flickering while non-declaring not?

ps. i got same results using size() and using public String sketchRenderer()

IMHO add a background(0); in the setup or even in the draw loop to test if it's better.