The problem with library apps isn't really the app. It's trivially easy to spin up a database with all the necessary fields. The real problem with library apps (or systems) is having to actually manage/index/code/scan the books, which is a pain.
Most books are in x39.50 catalogs, I have koha at home, using the British Library, Library of Congress, National Libraries of Scotland and France, and Oxford, it finds 90% of my books, barcode scan a shelf, import, add missing books
I got a barcode scanner and wrote a script to look them up in Open Library. Most of my books are found, but I don't have much weird/old stuff without barcodes. I found the process of scanning quite enjoyable tbh.
Yeah exactly, what would be awesome is an app that lets you take a picture of your book shelf and captures every book title (and author if possible)
And then after that step it could maybe build a small library with a nice, compact ui automatically