Ninchanese - Learn Chinese with Ninchanese and discover how addictive Chinese can be
HelloChinese - HelloChinese is the most fun and effective app for beginners to learn Mandarin Chinese.
ChineseSkill - Chinese language has and does deserve its notoriety for heartbreaking difficulty.
maayot - Mandarin learning with fun and engaging stories. Receive in your inbox a daily Chinese graded reader story with new characters, one-click dictionary, professional audio, etc.
Duolingo - Duolingo is a free language learning app for iOS, Windows and Android devices. The app makes learning a new language fun by breaking learning into small lessons where you can earn points and move up through the levels. Read more about Duolingo.
Rosetta Stone - Rosetta Stone is the world's most popular software for learning languages. It is offered at a cost of just $169 when purchased outright, but it is also possible to purchase language programs in a subscription format that offers ongoing support.