How to: Telnet With an iPhone
If you are accustomed to using telnet on your computer to connect to a remote server over the Internet, you might also want to telnet with your iPhone. Apple's iPhone is a cellphone with a multi-touch display that connects to the Internet via Wi-Fi and cellular data networks. The iPhone doesn't come with a terminal emulator application, so you will need to download a third-party app from Apple's App Store if you want to telnet with the device.
Press the "Home" button on your iPhone, located below the touch-sensitive display.
Tap the "App Store" icon on the device's home screen.
Tap "Search," then type "Telnet" in the search bar, and then tap "Search."
Tap the name of a telnet app from the search results, such as "Telnet," Mocha Telnet Lite" or "pTerm."
Tap the price of the telnet app, and then tap "Install." Type your Apple ID at the prompt. The telnet app downloads and installs on your iPhone.
Tap the icon of the telnet app to launch it.
Type "telnet" at the command prompt, then type the address of the telnet server that you want to connect to. Tap the "Return" button to connect to the server. Type your username and your password at the prompt.