Just click the panels. Just a little thing I made while I was bored. You can use this in your project(s), just give a bit of credit :D
The difference in the position of each panel is 88 pixels (vertically and horizontally for the bottom ones). To add a new panel, just adjust the positions. If you don't get the desired results after a decent amount of tweaking, then give me the link to your project and I'd be happy to help. Note: Adding more categories is a bit more complicated.