The Launcher tool is a convenient place to open applications and files that you work with often. You can drag & drop applications and files to its list to have access to them from within ADT and its globally accessible menus. You can also click the add [+] button and select the file or app to add from the dialog box.
The Launcher provides organizational tools as well. From the Action Menu, you can "Add Group" or "Add Separator" to keep the items in your Launcher organized and easy to find.
We recommend keeping a "Current Projects" group for quick-access to projects you're working on from several different locations.