The Launchpad is a pretty nice feature available since OS X Lion. This is a simple way to make your applications accessible, and of course to use them. Only problem, with time the application icons tend to accumulate even if you have removed some of them.

How To Clean The Launchpad In Mac
Here’s how to remove these orphaned icons:
1. Open Terminal
2. Type the following command:
rm ~/Library/Application\ Support/Dock/*.db ; killall Dock
You will not need to restart your Mac, all orphan applications will be gone. The disadvantage of this method is that it will suddenly recreate your folders in the Launchpad.