The AppManager panel lets you switch quickly between applications. You can use a key combination to cycle through the open applications without mousing through the application menu (the one with an application or Finder icon in the upper right corner of the screen.)
To switch back to the open application that was used just before the current one, type Shift-Command-Option-<left arrow>. <left-arrow> means the left arrow directional key, usually located between the main keys and the numeric keypad.
To switch to the next application in the Application menu type Shift-Command-Option-<right arrow>.
To switch between the current and last applications type Shift-Command-Option-/.
To change one of these key combinations, select the long box underneath the appropriate function, then type the key combination you prefer to use.
 
Hide Background Applications
To automatically hide the windows of applications that are not currently active, click the check box labeled “Hide Background Applications” so it is checked. This reduces clutter on the desktop and unnecessary window updates.
You can temporarily view background windows by choosing Show All from the Application menu.
