The entire game is free from start to finish, with the exception of a few in-app purchases, though from what I heard, you don't need them to finish the game. The game itself has Japanese voices but all the text is in English. The game is based off the Tales of Phantasia: Full Voice Edition that was released for the PlayStation Portable before (not the Cross Edition from Narikiri Dungeon X, so don't expect Rondoline to be here).
The game is compatible with iPhone4S, iPhone5, iPad2, iPad (3rd & 4th generation), iPad Mini and iPod touch 5th. Requires iOS4.3 or later. Lower model phones/iPads may run it, but expect issues or slowness. The entire game is 400MB, though it may also prompt you to be online at times, specifically for save files and a login bonus.