Unfortunately because Iphone/Ipod touch browser does not support Java application, the built-in XHMI1 applet cannot run on an Iphone.
But there may be third party Scada software for Iphone that supports Modbus/TCP protocol. If so it is possible to connect to the F-series PLCs that has a Modbus/TCP server. However, this is not available on TLServer or XServer.