All of the following apps allow you to manage your list directly via an iOS app.
Apps that merely import your list from MAL have not been included, as they're no different to full websites like Anime-Planet and Hummingbird that do the same.
'iMAL is a companion app for MyAnimeList.net. It lets you easily update your anime and manga lists directly from your iPhone/iPod/iPad.
It is available on all devices with iOS 4.4 or higher.
iMal is, and will remain, completely free and ad-free.'
'MyAniList is a beautiful app for MyAnimeList.net, written and completely optimised for iOS 7.
Keep track of what you're watching and reading with just a few taps. Easily explore new anime and manga and check out what your friends are doing, too! All in a simple by eloquent interface.'