Launchpad in OS X Mountain Lion includes a search field on top of the screen that makes finding apps easier. Type the name of the app you’re looking for and the display will filter to show only apps that match what you are typing in.
A quick way to launch app is to run Launchpad, start typing the name of app, and then hit the Enter key to launch the app. To make it even quicker, you can setup to run Launchpad at one of the hot corner of the screen. To setup the hot corner, go to System Preferences > Mission Control and click on the “Hot Corners…” button at the bottom.
Select from the drop-down list to setup Launchpad as one of the hot corners. In the above example, the left-bottom corner of the screen is setup to be the Launchpad hot corner. System will then run Launchpad whenever the cursor is over at the left-bottom corner.
Thus to quickly run the Reminders app for example, move the cursor to left-bottom of screen, type “rem” and then press the Enter key.