I’m building an e-book reader for the web and PWA platforms:

https://flowery.app/books

The library of public domain classics is courtesy of Standard Ebooks. I publish a book every Saturday, and refine the EPUB parser and styler whenever they choke on a book. I’m currently putting the finishing touches to endnote rendering (pop-up or margin notes depending on screen width) so that next Saturday’s publication of “The Federalist Papers” does justice to the punctilious Publius.

Obligatory landing page for the paid product:

https://flowery.app/vocabulary-building