Language/Mandarin-chinese/Culture/Internet-resources-for-learning-Mandarin-Chinese
Free resources for learning Mandarin Chinese. Those mentioned in Language/Multiple-languages/Culture/Internet-resources-for-polyglots are not to be listed again here.
http://www.rtega.be/chmn/
For remembering characters.
https://www.skishore.me/makemeahanzi/
About characters. It is open-source.
http://www.chinesehideout.com/challenge/
For learning and practicing characters and words. It also provides other options besides HSK.
https://mandarinbean.com/
Texts to read. They are so short.
https://hanyufanting.com/
For listening.
https://www.duchinese.net/
Free users can only read the newest ones. But there is no better alternative.
http://www.chinesetoolbox.com/
Program for reading.
https://hahachn.wordpress.com/internet-slang-glossary/
Internet slangs.
https://www.relativescalc.com/
Like a calculator, it helps to understand the forms of address of relatives.
http://fonts.jp/hanazono/
Hanazono contains more than 80k characters. If you are using Cangjie and feel annoyed to always see "tofu", this one can help.
https://wiki.gnome.org/Apps/Mahjongg
I couldn't imagine I can be fond of mahjong solitaire. This one can help to learn some common Kangxi radicals. I wish they can do more.