Ubuntu has a pop out drawer to store files and apps in the drop-down menu,with that you do not need to launch the frequently used documents,apps,images by locating them or clicking shortcuts on your desktop.You will also have a tidy desktop.
First,right click on a panel and select Add to Panel…,find out Drawer and click on Add button.
Now you will see the Drawer icon on the panel and you can move it to a proper place.
Right click on the icon and select Add to Drawer… Select Custom Applications Launcher and click Add.
The Create Launcher window pops up,click on the icon in the left of window to choose new icon.
In Type area select Application or Location to add a app. or file to the drop-down menu.
Type a shortcut name in Name area.
In Command area type a command or click Browse… to locate the file.
Add a comment in Comment area.
This is my drop-down menu,put your mouse on the icon and Name and Comment you typed will present to you.