In honor of Harry Potter Years 5 – 7 on iOS, Warner Brothers has dropped Batman Arkham City Lockdown to 99 cents. You can currently find this on your iPhone or iPad via the App Store. With that you can take command of Batman and fight off various villains from the series or try your luck with other characters like Poison Ivy.
Sadly there is no discounts on the additional costumes, so if you want to change your look it will cost you an additional fee. However this is still the cheapest this app has been in a while, so it is the right time to buy if you were on the fence.