Personally, I would wait until the Android release goes live and buy an Android tablet. More bang for you buck. However, as draketh said, this is all personal preference.
To download Battle Gems, you would go to the App Store, search for "Battle Gems" (without quotes), and download the app of Artix Entertainment.
You do not need a Facebook account to play, but it is advised, as you will be able to synchronise your gameplay with other devices.
< Message edited by Morlock Darccastle -- 3/18/2014 18:43:03 >