Nope...

For good reasons, I somewhen began to mistrust all apps I bought on this store
and meanwhile, I instantly start an analysis of the complete internet traffic
an app makes.

No „surprises" here…

This app uploads your data and more (e.g. cover photos you shot) without further notice.
[…]

Unless you really don’t care about your privacy, I would recommend to skip this app.

—
Update 1, to be fair:
BookBuddy does a great job on cataloging your books.
Scanning multiple books has its flaws, but none that would dramatically
slow you down. It has CSV im- and export functionality, a borrowing feature,
supports multiple authors, series and subtitels.
But to me, it’s all about transparency. If the developer doesn’t cater to it, I will :)

HP35z about BookBuddy: My Library Manager, v7.4.4