We're going to use the Documents by Readdle app to upload and download file through iUSBport device.
1) The iUSBport must be set in Infra mode (joining the existing known network).
2) Open up the Documents app and tap "Network" and add "Dropbox".
3) Type in the user name and password and sign in the Dropbox account.
4) Hit "Allow" to allow Documents to access all files and folders in Dropbox.
5) The Dropbox is added. Go back to step 1 and add "FTP Server".
Key in the assigned IP address "192.168.1.16" which is displayed on iUSBport device as the host.
6) Tap the "Dropbox", go to the folder and select the file to be transferred.
Tap the "Edit" button on the upper right corner.
7) The selected file "12 CN NO SAV.pdf" has a blue dot on and hit "Done" once it is ready to transfer.
8) Tap the "Download" to have the selected file downloaded to "Documents"
9) Once the selected files are saved in the "Documents", user can tap the "Edit" on the upper right corner and select files to be uploaded to iUSBport
10) Tap "Upload" and choose the upload destination "192.168.1.16" where is the iUSBport device.
11) Tap the "C" where is the attached USB storage device, and hit "Upload" to save the selected files.
12) To upload files from iUSBport back to the Dropbox.
Go back to step 5, tap "Network" and access to FTP Server.
13) Go back to step 8, select files from attached USB storage device and download it to "Documents."
14) Go back to step 9 and 10 to upload selected files back to Dropbox account.