No. It won't do anything at all on this phone, except possibly break it.
That app has nothing whatsoever to do with CWM, as 4EXT is a completely different recovery system almost exclusively used on HTC devices. That app is just a ROM Manager-like control panel for 4EXT.
If you read the app description right on the page you linked:
"At the moment the following are supported:
Incredible S / 2, Desire Z / G2, Desire S, Desire, Desire HD, Inspire 4G"