Similar to the ribbon tabs, App Studio features open panels that provide additional options to assist in the development of your application. Not all panels open at the same time, nor do they provide the same options. When you launch App Studio for the first time, only the Environments Tree panel appears docked to the edge of the canvas. The File/Folder Properties panel also appears, but is auto hidden.
All panels, except the Environments Tree panel, are auto hidden by default. You can control the visibility of the panels in the View groups on the Home tab and Utilities tab. You can also customize the appearance and placement of each panel around your canvas.