You can do that semi-easily on most linux apps using GTK, Qt with AT-SPI: https://delysid.org/gspi.html https://delysid.org/gspi.html most likely both Windows

You can do that semi-easily on most linux apps using GTK, Qt with AT-SPI: https://delysid.org/gspi.html https://delysid.org/gspi.html most likely both Windows and macOS would have similar mechanisms for accessing their respective accessibility api