USB Drive is a really convenient jailbreak app from Cydia that let’s you use your iPhone as a USB storage drive. This allows you to put any content on the device for easy transfer to another computer using your iPhone!
USB Drive allows you to use however much you want of your device’s capacity to create “partitions” in the app for storing content on. You can pretty much make as many partitions as you want, but it’s not recommended due to the fact that it might make your device slow and you don’t want to use too much of your device’s capacity. It has 3 different modes to offer: “Default” mode, “Drive Only” mode (which allows the driver only) and lastly “Drive + iTunes” (which allows you to use the driver and iTunes on your computer). It has been reported that the “Drive + iTunes” mode might make your iTunes not work properly but it’s only temporary. It is also recommended to read the documentation about the modes yourself.
You can get USB Drive yourself for free by adding the following repo to your sources in Cydia (Remeber, your device must be jailbroken!!):