B24 is a free online library catalog that allows users to access their library's WebOPAC and their reader account from their mobile devices. With B24, users can easily search for libraries based on location, GPS position, QR code, or from a list of available libraries.

One of the main features of B24 is the ability to search for media using the ISBN code. Users can scan the ISBN code of a book, for example, and check its availability in their library. B24 also provides a comprehensive search function within the library's online catalog, allowing users to find and view detailed information about the media they are interested in, including new acquisitions.

In addition to the search functions, B24 also offers convenient reader management features. Users can view their borrowed and reserved media, extend loan periods, and save search results to a personal list. B24 even provides a scannable barcode of the user's reader number within the app, making it easy to access their account information. The app also allows users to view library information such as events, news, and opening hours, as well as access the Onleihe digital library platform.

Furthermore, B24 offers a family linking feature, allowing users to view and extend borrowed media for their family members. This makes it convenient for families to manage their library accounts and keep track of their borrowed items.

To get started with B24, users can simply search for their library using GPS, QR code, or by entering the library's location directly. They can then log in using their reader number and password or access the app without logging in. The login information remains saved until the user logs out.

Please note that B24 only supports libraries that are partners of datronic IT-Systeme GmbH & Co. KG. If a user cannot find their library in the B24 app, it is likely because their library does not use the datronic library system.