Launchpad in OS X Yosemite
Launchpad presents all the applications in your Applications folder in a view that looks like the home screen of any iOS device (that is, iPhone, iPad, or iPod touch). In fact, if you use one of these devices, it works almost exactly like the home screen on an iPhone or other iDevice.
Click the Launchpad Dock icon. It fills your screen with big, beautiful application icons.
The Desktop picture in the figure was changed from plain white to a photograph (of Apple’s Yosemite web page). The photo is actually in focus; the nifty blur effect happens only when Launchpad is active. Sure, it’s just eye candy, but it’s elegant eye candy.
If your Launchpad has more than one page of apps, you can press Command+left-arrow or right-arrow to move to the previous or next page. Trackpad users can also use a three-finger swipe left or right to move from page to page.
To launch an app, just click its icon. In a heartbeat, Launchpad disappears, and the app replaces it on your screen.