They do not work. I have tried it on the GPE 4.2 and 4.3 and they just don't work. My guess would be that it is due to the black menu bar that some apps use. The phone looks at the black menu bar as "onscreen buttons". The only rom I was able to get the onscreen buttons to work on was CM 10.1. I tried it on CM 10.2 and it did not work. I think the black menu bar may be the culprit because if I disable onscreen buttons after trying to enable them, the black menu bar is gone but then there is no menu option. I have tinkered with it for some time now and haven't been successful.