We don't really need apps (or changing extensions) to freeze apps anymore unless they are system apps. Even the apps that VZW put on the phone can be frozen natively in android (haven't tried it with any system apps so don't know if you could but I'm going to say no).
Also, I'm sorry I didn't have enough caffine when I wrote my first reply, it is stopping apps at start up that can't be done in ICS yet.. Not freezing apps... /facepalm