Where do I change my user data like password or e-mail address?
You have the option to change your user data at any time directly within the app. This option can be found via:
iOS: Settings / Premium Status / Assigned to account / Change password
iOS:(for non-active Premium accounts or non-existent account connections) Settings / Premium Status / Activate Premium Service / Restore Premium / Change password
Mac: Preferences / Account / Manage Account