Business Skills: Learn Mandarin Chinese: good overview of why and how to learn Chinese. Lots of links to other great learning resources, too. Thank you Hailey for the suggestion!
FluentKey: free website with a library of authentic Chinese videos. Divided by language level and supported with comprehension quizzes, subtitles, and other games and activities.
FluentU: paid website for authentic Chinese videos.
ChinesePod: Podcast-style Chinese lessons. Additional paid features.
Popup Chinese: a huge library of free podcast or music video lessons.
Ting: lost of good listening resources, i.e. stories, games, read-alongs.
Reading Practice:
Chairman's Bao: read a huge library of leveled Chinese news articles, supported by audio, vocab, and quizzes.
DuChinese: a reading app for Chinese on an iOS or Android device.
Bliu Bliu: read from a corpus of authentic Chinese texts.
Clavis Sinica Voices: read over a hundred handpicked Chinese cultural stories divided by level.
CLQ Grammar Master List[IN PROGRESS]: detailed reference list of grammar structures in CLQ, including Chinese sentence structure, questions, numbers, time, directions, commands, descriptive elements, and transitions.
Vocabulary Practice:
Skritter: great software to practice Chinese vocabulary.