Hi Rebekka,
With the latest update to Notion for iOS, build 2.5, if you are running iOS 11 or higher, you will now have the ability to use the built in document manager from Apple that is part of iOS. This allows you to manage where you are saving files. Unfortunately, this functionality was not available in iOS 9 or 10 so with those operating systems, we are using our own Home screen. This functionality is being further looked at by our development team. Please take a look at the release notes for the next update to Notion for iOS. Unless you backed up your iPad via iTunes to a desktop computer, prior to updating, it is not possible to roll back. Thank you for your patience.