The Android rendition of Injustice: Gods Among US received a large (in scale) update adding online multiplayer among other enhancements. The addition of multiplayer on its own makes this game a lot better in some ways, giving it much more replay value.
With online play there are also online leaderboards for you to compete in. You can also now watch match replays, if you are into that kind of thing. Rounding out the update are multiple new characters; Shazam, Batman Returns Catwoman, Green Lantern Sinestro, Animated Harley Quinn, New 52 Nightwing, Arrow,and Krypto Lex Luthor.