Metroknight gives a pretty good run down, but there's a little bit of official documentation that might be helpful to: <a href="http://help.roll20.net/mobile-support/" rel="nofollow">http://help.roll20.net/mobile-support/</a> You don't have access to ALL of the Roll20 features, but the essential tabletop stuff works if I remember correctly. I don't think that video and voice chat does, however, since Roll20 uses both flash and WebRT for their stuff and most mobile browsers have problems with those. Also, I the devs are designing their mobile support for specific mobile browsers rather than as a standalone app. Ipads can use safari and android devices use the mobile chrome browser. I haven't tried it out since the early days of mobile, so I don't have any real advice, I'm afraid.