I write ViewingDale dice app which is very similar for the PC. It might work on a tablet PC but the program uses hardware graphics card acceleration to do it. You can switch that off if it whinges about that tho. Its a completely free app so try it here:-
http://www.viewing.ltd.uk/cgi-bin/vi...?category=dice
It also allows networking so you can remotely shake dice and you see other members dice rolls. And yeah it does d7 and d2 and expression parser up to 1000 dice, you have dice colors and types too like metal or plastic red, blue or all colors.
The next time I get an accelerometer for my big desktop box ill hook it into that so when I shake it about it rolls the dice... ok maybe not !
enjoy !