It is supposed to make your 3G faster and I decided to test it.
I tethered it to my PC with full signal 5 bars all the way through. (what better way eh? )
Anyway I did the experiment with and without the app, the results just might surprise you.
(The app does say it doesn't work with CDMA, however I saw a major improvement)
POST YOUR RESULTS FOR FURTHER EXPERIMENTATION, REMEMBER TO TEST WITH CONSISTING SIGNAL AS IT MAY IMPACT THE SPEEDS.
FYI - the only test results that can be used to determine something like this are those using multiple tests over weeks long periods. Network speeds, especially cellular networks, vary second to second. If the test is not being performed at the exact same time, you could see drastic differences from one moment to the next, without making any changes to your phone. Even during the test itself, speeds can vary dramatically.