iPhone devices started the smartphone craze which would go on to replace conventional mobile phones in both Japan (which had its own subset of cell phones) and the rest of the world, with more advanced touch-controlled devices.
Unlike their direct competitor, Android-based smartphones, they have currently no working emulators - as the official iOS SDK (Mac-only) only allows for running your own projects.
Many of the currently available "simulators" only try recreating popular iOS apps (like browsers) in a PC application with no real emulation involved. Some notable scams in such fashion are called iPadian or variations on the name, and are often adwares. A project to emulate various smartphones (iPhone, iPod Touch, iPad, Apple TV 2G) called iEmu, started in 2011 but got mysteriously abandoned two years later before anything usable surfaced. There has been recently a project to convert iOS apps to Android apps but nothing released yet as well.