Looks an interesting app and does solve a pain point I encounter semi-frequently.
I'm usually not one to comment on prices of applications, but $50/$100 for such a small utility is pretty steep. At 20 dollars I may even buy for it occasional use and not even think about it. At your prices I need to compare it to Affinity, kaleidoscope, littlesnitch and see if I derive a similar value from your application.