Hello Gabriel,
Inside content of your app select a pen icon (add) and you will find two options for creating categories.New Category – which will enable your app users a site navigation or arrangement of your appTwo columns – creates a category , which has the half size of the device. If you are referring to the Sidebar, you should select Sidebar Actions where you can add a certain Page from your content. If you want it visible only in the Sidebar, you can easily hide it from the Main page by using the option Hide in the Design section of the Main page.
