Hide and unhide Mac App Store purchases
If you’ve downloaded a lot of applications from the Mac App Store, your Purchases list may get really long—too long to be useful or navigable. If your Purchases list is getting unwieldy, you can hide some of the apps on it. OS X Hints reader rombaldi found a way to do just that—and then undo it later if you wish. Note that this trick is similar to, but distinct from, a technique that works in the iTunes App Store.
In the Mac App Store, go to the Purchases tab and hover your cursor next to the Install button of an app you want to hide. A small X will appear; click on that to hide the app.
Bringing hidden apps back is simple, too, if slightly less intuitive: Click on the Account link on the main page of the Mac App Store under Quick Links. Enter your password, then click View Account. If you’ve deleted at least one app, you’ll see an iTunes in the Cloud section in that account window. In that section, click View Hidden Purchases, then click on the Unhide button for any apps you want to return to your Purchases list.