Some of you might see this message when trying to download the app from the Mac App Store: "The current version requires OS X 12.0 or later, but you can download the last compatible version," even though you're on macOS Catalina (10.15) and "OS X 12.0" doesn't currently exist.
Simply ignore the message and click Download to get the latest version of the app anyway. We're investigating why the confusing prompt pops up for some of you, so if you're affected and want to help, feel free to send us your diagnostic data. Please open GoodNotes menu (Gear icon) in the top-right corner of the library view > About > Export Diagnostic Data, save the file, then send it to firstname.lastname@example.org. Thank you!