At some point "very soon," Phoenix Wright: Ace Attorney - Dual Destinies will be making its way to iOS. It's already live on the Japanese App Store, so it's just a matter of waiting and seeing when us Western gamers can enjoy the delights.
Previously solely a 3DS game, Phoenix Wright: Ace Attorney - Dual Destinies is the fifth game in the Ace Attorney series, with you having to solve various court cases by gathering up evidence and determining contradictions in witness statements. I've played the 3DS version and it's excellent. We can only hope that the iOS version comes to our virtual shores very soon.
We'll be sure to keep you in the know.