I bought this. The dev has a Mac version and just came out with a Windows beta version. It's super useful. I can completely eliminate my use of the mouse if I want to, which helps a ton when working on my laptop since I don't really like using touchpads.
The lifetime license for the software has per-country pricing. In the USA, it's priced at $20, which is pretty good for such a useful tool. I'd much rather pay a lifetime license than a subscription.