It is a true put-off to read on Version Tracker that the software is "freeware" and then to launch the app only to be asked for a donation and for there to also be a registration number!

I have not tried your application yet... The concept is great!

I'd also suggest that you provide more than only PayPal as an option for making the donation... I will not do business with PayPal! Try one, or better all, of the following:

https://order.kagi.com/cgi-bin/home.cgi

Google Pay

http://store.esellerate.net