Meta data like title or author depend on the ebook, not all documents have complete or valid information. To sort books by the author’s last name, the required file-as attribute must be correct (e.g. Shakespeare, William) because otherwise the order can not be determined.

You can either fix meta data before you import a book in calibre or adjust it later. When editing a book in Yomu, tap the right swap button (two arrows) next to the author’s name (see screenshot). This lets you manually change the file-as property.

To sort your library by author, you will also need to change the library sort option (bottom right 3 dots) to author. Refer to the guide for additional details.

Yomu supports basic epub 3 standard series and proprietary Calibre and ComicInfo metadata formats. You can also manually enter series name/number for others by editing a document as described in the Get Started Guide.

If you imported books before series metadata was available, you will need to migrate your library. Data migration scans your library and updates documents where series metadata is found: Settings > Data > Migrate data > Book Series

When you edit metadata like title, author or series in Calibre, it’s only saved in their internal database and not in the original file. You might need to first write back your changes to the embedded metadata in the ebook files. You can either use Save to disk or Polish books with update metadata enabled. For more information, see this Reddit post and MobileRead thread or refer to the Calibre manual.

You can manage your books or add and edit folders and tags on your Mac. To switch to editing mode, click the top right Edit Library (pencil) toolbar button.

Alternatively, you can edit an individual ebook by using its context menu. Right click a book in your library to show the corresponding menu.

For general information about editing books, refer to the guide.

In editing mode, click on either Add Folder or Add Tag in the left sidebar to create new folders or tags. Click on the edit icon (pencil) next to a folder or tag allows to change the name and the delete button removes it from your library.

Folders or documents can also be sorted. Because direct inline sorting is not supported, a new window will open that lets you drag & drop folders or documents to change the order.

Please note: due to a system level issue on macOS Catalina, drag & drop outside the window frame can lead to a crash. There is no fix available, you would need to update to macOS 11 (Big Sur) where this should be resolved.

Your library and reading progress can be automatically synced with the pro edition. Books, annotations, folders, tags and reading progress are stored securely in Apple’s iCloud service. Every time you change something on one device, it’s synced to all your other devices.

But the cloud library is an optional pro feature, you must first manually enable it for all of your devices. See the Cloud Library FAQ for more details.

Other options for synchronizing books or reading progress are not supported. For OPDS servers and comics, it should be possible with reader apps that support the OPDS Page Streaming Extension (OPDS-PSE). However, there are currently no plans to integrate this (unofficial) extension, as it just works quite differently.

You could try to automate this with Apple Shortcuts if an API is available. Yomu provides actions to get your current or any book, it contains all meta data and also includes the current reading progress. Additional details and examples are available in the Shortcuts FAQ.