OpenSSH is a background system that allows you to connect to your iPhone over wifi and transfer files from your computer to your iPhone. Note: No icon will appear for this app.

1. First, you will need to use the Installer.app and install both BSD Subsystem & OpenSSH on your iPhone.
(update:  If you have used ziphone 3.0 it will automatically install BSD and OpenSSH)

Click on picture to enlarge

Click on picture to enlarge

2. Then you will need some type of SSH client installed on your computer. WinSCP is great for PCs. Macs come with openssh but if you’d like some alternatives check here.

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3. To upload files to your iPhone just follow the instructions that come with the SSH program you’ve installed on your computer. To sign into the iPhone, the host name is the iPhone’s IP address which you can find on your iPhone under Settings then Wi-Fi then tap the arrow next to the wifi you are connected to. The username is root and password is alpine for v1.1.1 and newer, for older versions the password is dottie.

Helpful Hints:
- The first time you connect it takes longer than usual, about 30 full seconds.
- You’re iPhone must stay turned on, so disable autolock
- You’re iPhone and computer must be on the same network, ssh connects via wifi on the iPhone.

Source (http://www.appleiphoneschool.com/)