Well this feels like it kind of came out of nowhere. I thought I was keeping up on all things Injustice and then, yesterday, I find out that they released an iOS version. I spent some time playing it and it's actually quite fun. The game is set up a little differently than the console versions. You play through a series of ladder battles with a group of three superheroes or villains that you can tag in at any time. Along the way, you'll earn booster cards to improve your team members' stats and coins that allow you to buy new characters.
It's a free download for anyone with an iOS device (iPhone, iPad, or iPod. No word on an Android version) so there's really no reason to not at least try it. Maybe you'll get lucky and Green Arrow will be part of your starting team. Then you won't have to spend all of your coins to get him like I did.