Forvo - Forvo: the largest word pronunciation dictionary in the world, now with translations.
SmartCards+ - Spaced Repetition Software for iOS. Modern, powerful and easy to use.
Howjsay - Pronounce words correctly with the world’s largest English pronouncing dictionary.
FlipToMind - Space repetition app to help you remember everything
Shtooka - The Shtooka Project is a multilingual database of audio recordings of words and sentences.
Zorbi - Spaced-Repetition Flashcards - Other tools are built by boomers, Zorbi is built by students.