Hey all!
Thanks for posting this, Smiley, and linkifying the URLs, Laithoron!
I'm GM Toolkit's developer and I'm happy to answer any questions. Feel free to shoot them my way either here or through the Web site (or the Kickstarter).
I use the app myself, initially for a Pathfinder campaign I was running. I've since started a Savage Worlds "50 Fathoms" campaign and I'm using it extensively there.
Cheers!
Peter