Make sure you follow these directions. If you try to open it, it will just give you an error screen.
To use it, after it is installed...
From the Home screen - press menu>settings>sound and display>phone ringtone or notification ringtone. A pop up will ask what program to use, choose rings extended. You will have access to other ringtones, mp3 files, or sounds that you have on your SD Card.
If you have a 3rd party text like chompSMS, you will have to customize the sounds through that application.