I know I'm cheap and I know this app is great and is a lot of work but fuck, this is expensive.
Subscriptions are the worst model capitalism can offer. And the one time payment price is ridiculous, I can't afford that.
Realistically it's the only way he can sustain the development costs with such a small userbase. I've subscribed monthly to show my support. It's not really that much money considering how much I use sync.