MosaLingua was designed by a professor and 2 developers who actually uses MosaLingua on a daily basis.
Learn the essential 20% that will apply 80% of the time. Afterwards you can choose an area of focus that is relevant for you (travel, sports, business, technology…). Spending just 5 minutes per day for two months will allow you to memorize 600 words and key phrases!
Whether you are starting from scratch or you already know the basics, MosaLingua is adapted to suit your language needs. It's like having your own private tutor in your pocket!
https://play.google.com/store/apps/details?id=com.mosalingua.deu