eZi Test helps you memorise Mandarin Chinese characters and words, based on the HSK and Unicode, in English, Deutsch, française, española. Unlike other apps that force you into a training program, eZi Test puts YOU in control of what you learn.

For instruction: http://itunes.apple.com/us/app/ezi-test-chinese/id384300792?mt=8
To load the app on an iPhone, search in the App store for "eZi Test Chinese"