Something's missing on yoon.bitcron.com
I read your page yoon.bitcron.com/post/ios/2019-01-24 and have two words: incredibly useful! I loved the font-related resources you mention there. (sorry for the email in English, it's easier for me to read than write in Chinese).
I tried a few fonts, but soon after I realized that I couldn't use many of them for work-related materials because they are not for commercial use - quite a disappointment, to be honest.
Anyway, I did some digging and found a list of fonts that are free for commercial use too! (And super well organized, but not my point here!)
Since your readers might need fonts for commercial purposes, I do believe they'll find it useful if you add it to your page.
Thanks again for the resource!