I started using this after openaudible went behind a paywall: https://github.com/audiamus/AaxAudioConverter

Don’t they charge like $10 a month now?

Books are pretty easy for direct downloads. Try these: https://libgen.is/ https://annas-archive.org/

Megathread: https://fmhy.pages.dev/

That landing page is pretty clever BTW.

What would you say are the best reasons to prefer your app over obsidian?

You need a piece of software to do it. I know of one for chrome and for Firefox, so depends on your browser. Saw how to do it on a reddit post a year ago or so. Its always a pain to find again.

EDIT: here it is: https://www.reddit.com/r/Piracy/comments/fm1xpw/internet_archive_borrowing_picture_books/

The hourly ones can be scraped from IA if you flip through all the pages in the online interface and use a cache viewer for your web browser. Then you have to stitch all the images together into a pdf.