YNAB 4 is a 32-bit application that will not run on macOS beginning with macOS Catalina. Catalina is the first version of macOS to exclusively support 64-bit applications.
This shell script will convert the final release of YNAB 4 for macOS (v4.3.855) from a 32-bit app to a native 64-bit app so that it will run on macOS Catalina without the need for an emulation or compatibility layer. You will still need a valid license key to use the 64-bit version of the app.
And for android you can use the last apk: