How to play audiobook files?

To play your .m4b audiobook files on Windows and Mac, you can use the following apps:

Windows:

1. iTunes: Supports .m4b files natively and allows you to manage and play audiobooks.
2. VLC Media Player: A free and open-source media player that supports almost all formats, including .m4b. In VLC media player, you can also go to the ‘Playback’ menu and select the ‘Chapter’ option to view a chapter-by-chapter breakdown of the audiobook file or to jump between chapters.
3. MusicBee: A great media manager that supports .m4b files and offers audiobook-specific features.
4. Audible app: Although designed for Audible content, it can support imported audiobooks in certain formats like .m4b.

Mac:

1. Apple Books: Built-in app on macOS, where you can manage and play .m4b audiobooks seamlessly.
2. VLC Media Player: Works on both Mac and Windows, supporting a wide variety of formats including .m4b.
3. iTunes (for older macOS versions): Older macOS versions still use iTunes, which also supports .m4b files.
4. Plex: If you want to create a media server, Plex can support audiobook playback.

These apps will allow you to play your .m4b files easily.

To listen to your .m4b audiobooks on mobile (Android and iOS), you can use these apps:

Android:

1. Smart Audiobook Player: A dedicated audiobook player that supports .m4b files with features like bookmarks and playback speed control.
2. VLC Media Player: A versatile media player that supports various formats, including .m4b. It’s available for free on the Play Store. 
3. Audiobook Player: A simple and easy-to-use app that supports .m4b and .mp3 formats.
4. Plex: If you store your audiobooks on a media server, Plex allows streaming and playback of .m4b files on mobile.

iOS (iPhone/iPad):

1. Apple Books: Built-in app on iPhones and iPads that supports .m4b files. You can import audiobooks into the app via iTunes or the Files app.
2. VLC Media Player: Just like on Android, VLC on iOS supports .m4b files. 
3. Bound: A paid app that supports .m4b and other audiobook formats, with additional features for importing audiobooks from cloud storage.
4. Audible: Though primarily for Audible content, you can import .m4b files to Audible on iOS through specific methods.

These apps will let you listen to your audiobook on mobile platforms, offering useful playback and organization features.