This is an odd app - it uses a weird one-off design language that doesn't really fit with any Android version. It's quite useful but has some odd lacunae -- for example why aren't the book entries in 'loans' and 'reservations' links to the catalogue entries? Why do some of the links from the app's front screen (eg. 'mobile library stops') go to a full-page web view with no back button? All in all I wonder if the RTL would be better off just making a PWA, as most of this just seems to be thin wrappers over the web site, or just plain web views, anyway. And please, when you do an update, add release notes to the Play Store entry! Don't expect a user to blindly obey and install without any idea what's changed.
Easy to use Love that I don't have to keep putting my card number in each time. The barcode scanner feature is great when you're in a bookshop and want to check if the library has the book.