These are instructions on how to increase the volume on your 1.1.4 iPhone using an Installer source. Remember your iPhone speaker isn\’t very powerful so it will only be a slight improvement but its better then before
1 – Press to launch Cydia from your Springboard.
2 – Press to select the Search tab at the bottom of the screen.
3 – Type Volume Boost in search bar and search it.
4 – Press to select Volume Boost from the list and install it.
5 – Press the Install button at the top right hand corner of the screen.
6 – Press the large red Install button that appears.
7 – After installation it may ask you to reboot your device.
8 – You will now notice an increase in the volume of your phone
How to Install :
1. Your device must be jailbroken.
2. Search for iPhone Volume Booster in Cydia, run the install.