Du Chinese is one of the coolest apps out there for learning Chinese naturally through reading and audio. I use it especially for the context-rich stories and sentence translations.
Skritter is an awesome way to learn Traditional and Simplified Hanzi (Chinese characters) as well as Japanese Kanji.
Get 10% off a subscription by signing up on the desktop website here. Then you can download any of the mobile apps.
The discount code is already applied on the link!