How to delete or track the sign-in information on an iPad?
Third party apps can securely store and retrieve the login session information in the iPad's keychain (which unlike macOS keychain is not user accessible). The apps often does that so that it makes it seamless for users to log into other app(s) from the same developer (Both Google and Adobe publish multiple apps on the App Store).
You can take either one of the approaches (as made available by the developer of the app) to disassociate iPad from your account or log out from iPad:

Login to manage your account using a desktop web browser (such as for Google or Adobe), access the logged in devices and disassociate the device.

Get access to user account management within one of the apps on iPad and exercise the option to remove your account from log out from it.


An app developer would generally provide either one or both the options for users.