by default, it only disables the APN while the screen is off. This allows you to do what ever you want to do with the screen on and why you see the 3G connection. If you scroll thru all the text in the app, you can see where it disables the connection and re-enables it during times your screen is off. All it is doing is limiting the apps from being connected all the time, to a couple minutes every 15. I am not sure what got me the most improvement, but I was using Locale and stopped about the same time I started with this app. I can now make it 20 hours on a charge, were before I was real lucky to make it 15.