FRITZ!Box 6430 Cable Service - Knowledge Base
Using printers connected to FRITZ!Box with Apple iOS (e.g. iPhone)
USB printers connected to the FRITZ!Box can only be used with iOS devices (iPhone, iPad or iPod touch) if they support Apple's AirPrint technology. If you connect such a printer to the FRITZ!Box, then all of the iOS devices in the home network can use it.
iOS devices can only use printers that do not support AirPrint if you use additional software such as handyPrint, O'Print, or Printopia. The software must be installed on a computer connected to the FRITZ!Box and it then configures the computer as an AirPrint server. iOS devices then send print jobs to the computer's AirPrint server, which in turn sends them to the printer connected to the FRITZ!Box.