This looks like exactly the kind of thing I've been searching for, and I'm happy to pay a one-time price. I'd much rather own than subscribe.

Two things:

1. Will the local storage version be dependent at all on your servers? In other words, if I buy it once, can I use it forever even if you stop supporting it?

2. I would hit "buy now" today if there was a limited trial period before I was charged for it. $90 is a fair price for software (a little high, tbh, but I don't know another app that can do this) but I wouldn't pay that without having the chance to do a test drive first.

Best of luck, this looks awesome and I want to see it succeed!