A new version of the organizer generator is now available here. The separators and grid editor is more powerful and easier to use, and the generated organizers now integrate more seamlessly with Gridfinity.
Unit size in mm
Size in units
Joint friction

Use 0 for stackable objects with no friction and a négative value for a tighter fit. -0.065 seems to be a good value, but you may have to adjust it depending on your printer/nozzle/plastic type, ...

Compartments
[row height : cols widths (ex: 1,2,1)]
Low definition rendering
The downladed model is generated with a higher resolution than the preview above. So it can be slow. Be patient.