Under iOS: In the respective areas of the app you can select "Photos" or "Files" and then download them via the download icon. The photos are now visible in Apple's "Photos" app. Videos are currently not available for download.
Files are downloaded to the'Files' app of the iOS.
With Android: select the content you would like to download. Then click on "Download" below the three dots at the bottom right. Files are saved into your phone's "Downloads" folder, photos and videos in the "Pictures/myCloud" folder.