By creating a new Master Page, you can add headers to all pages in your app project. Here's how it works.
From your project overview tab, start by creating a new Master Page named "Header".
Double click on your new Master Page to open your studio editor, then click on the "Page Information" and set the background to "transparent."
Open the asset drawer to add images you've uploaded for your header, then reposition them using the layer alignment tool.
Hit save, then open another screen in your project. Select the page information panel, and apply your new Header master page.
Now you'll be able to add repeating menus and other elements to any screen inside your app. Don't forget to leave enough room at the top of your app screens for your header.