Application requirement :
1. Jailbreak
2. iPhone OS 3.0

Steps to install USB drive on your iPhone
1. Open Cydia
2. Go to Manage => sources
3. Press Edit on top right corner and then press Add on left corner. A input box will appear.
4. Enter http://apt.dmytro.me and press Add Source
5. Cydia will now add entered source. After successful addition of the source, press Return to Cydia button.
6. Now tap on Done button on right corner.


7. Tap on listed source. This will show you USB Drive application and other applications from this source.

8. Install this application as you normally install any application from Cydia.
9. After successful installation of USB drive app, Launch USB Drive application by tapping the USB Drive icon on the main screen.
10. You’ll see three modes
Drive + iTunes:
In this mode USB Drive replaces Picture Transfer Protocol (PTP) interface with Mass Storage interface and lets you use the iPhone as a USB Drive. At the same time you can perform iTunes synchronization, developers can use XCode debugger ,etc. In this mode USB Mass Storage will not work on Windows with iTunes or Apple USB Drivers installed.

Default:
This is the iPhone default mode. USB Drive doesn’t install daemon application nor modify any USB settings. Picture Transfer Protocol (PTP) is active as well as iTunes synchronization and tethering over USB.

Drive Only:
This mode is to resolve compatibility issues with Windows and iTunes. In this mode USB Drive changes the iPhone’s USB product ID. This will prevent iTunes synchronization, but USB Mass Storage will work on Windows (and other operating systems). Switch to the Default or Drive + iTunes mode will restore iTunes sync.

11. Select the mode of your choice and click on Create drive

12. Enjoy your new USB drive.