To begin with, Street Fighter may be my least favourite fighter series comparing it to Smash Bros., Dead or Alive or Soul Calibur and Capcom may not be my favourite third-party company out there because of their negligence of Mega Man, their constant re-hashing of the same goddamn Street Fighter game and their other issues, but I have to say that Street Fighter X Tekken for the iPhone/iPod is a solid fighter game.
I bought this game on October 2012 for my iPod because it looked like a great game. The game contains an Arcade mode, multi-player via Bluetooth and Wi-Fi, and Training mode. The story arc involves an object which crashed to Earth known as 'Pandora'. It got this name because of the effects it had on the characters. There is a Gems System which activates a roulette that gives you a random power-up every time you do a Launcher Attack on them.
What I like about this game is the graphics, the fast gameplay and the Gems System which can turn the tables on anyone as soon as it is used.
The negatives for this game are the online which takes ages to find a random opponent and the lack of content compared to the PS3, 360 and PSVita versions. There are only 12 characters and a few stages, which puts to question if the game should be £1.99/$1.99. I think that Capcom should have re-thought the overall price tag for the iOS version as I think it is a bit expensive for a game which has little content.
Though people would rather get the console versions of the game, the iOS version is a good game to look at if you want a fighter on-the-go.