First time, I wasn't impressed either. Until, I realized I had the wrong app. The exact search term is " Volume+ (Sound Boost) ". You can copy & paste that into the android market search field minus the quotation marks. The free version doesn't have sound boost in it's title and the volume level won't go up high enough. In preferences in the app, you need to be able to select somewhere between 8-10. Too low, nothing and too high doesn't work either.
Very important, when you download the app for the first time, there is quick one time visual tutorial. Do everything exactly what it says to do, if not, won't work. If you can take screen shots of the directions, your better off. After the one time, you would have to un—install and than re—install to see it again. It only comes up right after the initial install.
The only variance is your volume number in the preferences . Test, if it's working, by listening to the preset ring tones in the system settings of the phone.
I was afraid, that I might of had to exchange the phone because the speaker volume was so bad. This app makes a significant difference.