Thanks, Bill. I know of the Google results. Just wondered if anyone here had something they'd used in the past that they might be willing to share.
As far as making money and the developer buggering off, I don't expect that this will make really any money. It's going to be; if it ever gets done, a niche app for a subset of photographers. There's no competing product out there right now so that's a plus, but it'll still be a niche offering. I'd love to be able to do it myself but I'm not a programmer. I could learn but by the time I did I'd likely be in my dotage and beyond caring.