Careful! The option to download an entire album is currently only available in the desktop version of the application (via a browser on a laptop/PC).
Open the Kinderpedia page and access the "Media" section from the menu on the left, then click on the desired album.
To download the album, click on the "Download album" button on the right side of the page.
A window will appear in which you will see the size of the album and you must confirm the download.
Wait until the archive is ready for download, you can come back later if you want.
When the archive has finished processing, you will see the green "Download now" button.