Alternative launcher tools are ten-a-penny, and while many of them are perfectly functional, they have a tendency to feel like a bolted on extra. QuickPick is a little different in that once it is up and running, you would be forgiven for thinking that it was a part of OS X.
Although OS X already features the dock which can be used to store app shortcuts, but there is a limit on the number of icons that can be stored in a small area at the bottom of your screen. It makes sense to restrict using the dock to being a repository for your most frequently used apps, but this makes it more difficult to track down the apps you use less often.
QuickPick works in a similar way to Expose, and is activated with a keyboard shortcut or a mouse gesture. Use the shortcut and everything that is currently on your desktop will disappear enabling you to see the folders and icons you can use to launch your apps and documents.
Icons can be rearranged in whatever way you feel works best for you, and if you find that you have a very large number of icons you need access to, additional pages of icons can be created. QuickPick takes the best elements of Spotlight, Finder, the dock and Stacks to create a unique way of accessing your app and files.
QuickPick could be seen as slightly gimmicky with its gesture activation, but it is something that works well and greatly extends the capabilities of the dock.