I just read your homepage, and respectfully, it does NOT mention that it will not work with Monterrey. What it does say, is, "For OS X up to Mojave, NOT Catalina..." that is adjacent to the 32-bit download link. I DID read this at the time of download Since my MBA M1 running Monterey doesn't fall under this category (vis-a-vis 64 bit download), and I (as I'm sure the gentleman who created this thread) interpreted that FtF would function appropriately on the latest Mac OS.
So, I DID read your homepage. I read it carefully. If I was supposed to interpret that FtF for Mac wouldn't function on my OS based on the message above, well that my friend.... is on you, not us. You should be clear that the, "For OS X up to Mojave, NOT Catalina...." INCLUDES the 64 bit download.
Better yet, put a special message stating something like, "Neither FtF 32/64 bit versions currently run on Mac OS 10.15 and higher. Expected updated launch date is mid to end June, 2022. click here if you would like to be notified when it is released".
A message like this would be crystal clear and helpful those looking at your app. It would have saved me much time troubleshooting the issue.
BTW: Cool app :-). When the update does come out, I plan on purchasing it. I just wish I could do so now as I could really use it now.