We recently mentioned the Plex Android app (still selling for £1.27, incidentally), and here the iOS version is half price, too, currently going for £1.49 at the App Store. Plex is, in a nutshell, a personal media organiser.
Compatibility: Requires iOS 5.1 or later. Compatible with iPhone, iPad, and iPod touch. This app is optimised for iPhone 5, iPhone 6, and iPhone 6 Plus.
(Thanks to rubenm85 at HUKD)