Using the FTPManager app on iPhone, https://itunes.apple.com/us/app/ftpmanager-free/id525959186?mt=8
1) Open up the FTPManager, and tap "Add FTP Server"
2) Type in the Display Name as you like.
If the iUSBport is connected with iPhone in Ad Hoc mode, key in the default IP address "192.168.0.1" in FTP Server.
If it is connected in Infra mode, the assigned IP address is displayed on the iUSBport.
3) The "iUSBport" is added under the FTP Servers.
Tap it and the next screen will show the external USB storage which is connected to the iUSBport device
4) The "C" is the external USB storage device.
5) Tap the "C" and access to the folders in the external USB storage device
6) Tap the "Edit" at the upper right corner to select the files/images to be transferred
7) Tap "Download" to transfer selected files/images to Camera Roll in iPhone
8) Tap the Camera Roll and hit "YES" to begin transferring
9) To upload images from Camera Roll to the ext. USB storage device, please go back to step 3.
10) Tap "Photo Library" and then hit "Edit" at the upper right corner to select the images from Camera Roll
11) Hit "Upload" and the next screen below will be displayed
12) Tap the "iUSBport" and select the "C" where is the external USB storage device and tap "Save"
13) The selected images are uploaded to the external USB storage device