It is nagware - will work forever but with a nag screen (like WinZip back in the day), and IMO it is definitely worth a one time fee of $50 if you don't mind using closed source.
I actually didn't know that Fork can be bought! I installed a Beta version a while back, upgraded regularly and never have been shown a nag screen. Gladly paid for my license a few minutes ago.
Fork is one of the few pieces of software I used in beta where I thought, "You're not asking for money right now, but you seriously need to let me pay you for this."
It is nagware - will work forever but with a nag screen (like WinZip back in the day), and IMO it is definitely worth a one time fee of $50 if you don't mind using closed source.
But it is not quite the same category as Guitar.