The result of two decades of work, this app is designed to give you the fastest time to learn the vocabulary for any language. The software works out what words you're having trouble with and focuses on those words, while reminding you often enough with the words you do know so that you don't forget.

It can translate and pronounce over thirty languages. There are a number of word lists already built in. French 3,000. German 3,000. Latin 1,000. Chinese 1,000. Spanish, Russian and more. If you don't know the meaning of a word, it will even translate it for you.

While testing yourself, the software can read the words and phrases out to you, which helps you develop the right pronunciation.

You can create word lists as a CSV file on another device and email them to yourself and read them in, in the app. This is great for teachers to send out vocabulary to their students and even for students to share vocabulary with each other.

Leitner also has an experimental sleeping function, which plays words and phrases until you're in deep sleep by detecting your motion. Just put your iPhone under your pillow. Or alternatively you can set a timer and listen to the words and phrases with their translations. It's even useful to listen while driving or doing housework.