This is a stock MMS application for CM9. The only change is that it is dark holo themed instead of light.
This will not work on TouchWiz without modification or running it alongside of your stock mms application.
It's a system app. Use a root explorer to move the application into your system/app directory, or, even easier, push it to /system/app with adb:
adb push Mms.apk /system/app