YSK: There is a modern free and public domain ebook library app at BookDark.com based on Project Gutenberg where you can search and explore ebooks by authors or tags.
from /r/YouShouldKnow
YSK：在BookDark.com有一个基于Project Gutenberg的现代免费公共领域电子书库应用，你可以按作者或标签搜索和探索电子书。