I have hidden the Gallery page on the website but my Gallery folders still appear on the mobile app.
To hide the Gallery folders from appearing on the mobile app, go to the Gallery page on the website and individually hide each folder. When a folder is hidden is appears with a line through the folder name.
In the image below, the Gallery page on the website is hidden but the folder called General is still visible from the mobile app.
Registration forms are appearing on the app and I do not want these to be visible.
When you create a new online form it is automatically set to be visible in your mobile app. If you do not want a form to be visible go into Online Registrations, edit the form (by clicking on the pencil icon), click the orange ADVANCED OPTIONS button, untick the checkbox Visible in mobile app then Save. The online form will no longer be visible via your mobile app.