My experience with table top has been totally online. I have used a few tools out there with groups but mostly roll 20 recently. Is it cool if we use Roll20 as a testing grounds for our RPGs?
As long as your final entry is in .pdf format, using Roll20 (or any other online tools) to test your game is totally fine!
Edit: I've gone in and added Roll20 to the Useful Resources thread as well.