This is a fantastic tool! Can I contribute something since I feel so guilty for being a leech?
Absolutely. You can do us both a favor and buy GridBuilder for US$10. Its cheap, you'll be contributing to the continued development of a great free tool and you'll get something useful for yourself in the process.
And lets not forget the great-great-great granddaddy of GridMonger was the QuiKGrid VTM. Read about that and what you can do about it here.