Just a simple box generator. Save on material by avoiding solid walls. I also have a round version.

Sometimes you need a box to transport other, more delicate things you print. There are a number of box customizers on Thingiverse, but most of then generate boxes with solid walls, which consume a lot of filament. Use this to make a box with lattice sides and save yourself some money.

If you use OpenSCAD, you may find the lattice functions useful in your own designs.