The series consists of seven episodes. The remaining three episodes will be released for iOS soon. The game is also coming to PC & Mac, but no release date has yet been announced.
In other Telltale iOS news, the site is having a sale on iOS games. Most of Telltale's iPad and iPhone/iPod Touch games are $0.99 until January 29. You can view the games on sale along with links to buy them from Telltale's blog.