If you want to cleanup OS X Launchpad and restore to default you can use OS X Terminal. The command resets the Launchpad with the default content sorted on a to z basis.
Change the layout (rows and columns) of Launchpad
Did you know that you can fully customize the layout of Launchpad? Not only change the placement of icons, but you can also change the number of rows and columns. Use the following commands in OS X Terminal.