i don't mean to diminish your work at all - it really does look great and i mean that, and hopefully you'll prove me wrong, but i don't think you've properly considered what value this actually provides to the people you want to buy it.

you might say that $49 + an annual subscription (and it is a subscription by the way, you can call it what you like but that's objectively what it is) is what you need to charge in order to make the time/effort you spent on development worth it for you, which is fair, but consider it from the POV of a potential customer: it's $49 + an annual subscription for a prettier way to achieve something that they probably use quite rarely, something they can already do, and something which there are already free alternatives to.

consider something like bettermouse (https://better-mouse.com). macOS is borderline unusable without it, i'd sell my computer and switch to linux that same week if bettermouse disappeared. i make use of it for 100% of the time i use my computer, and it costs $7.99 one time, forever. the developer could double or even triple the price, and it still wouldn't even be half of what you're asking for.

Off topic, but can you tell me exactly why?