Mosalingua is offering Learn German Premium for free. Only Android is on sale, no iOS.
Learn German in no time! MosaLingua's effective and addictive teaching method will help you memorize loads of vocabulary, key phrases and conjugations in record time. By using the dialogue exercises, you'll be able to improve both your German comprehension and your speaking skills at the same time.
MosaLingua was designed by a German professor and a developer who actually uses MosaLingua on a daily basis.