Flashlight apps for iOS (iPhone and other iOS devices) are mostly third party apps. However, almost all Smartphones have their default, integrated app in the operating system.
Below are the links of the most used Flashlight apps for iOS, for iPhone and other apple devices:
Flashlight for iPhone, by iHandy inc. It goes with a compass, that gives you a direction in the dark.(link)
Police lights for iPhone by Francis Zorrilla. Police flash light and siren.(link)
Magic Lights by TLogic.de. Disco light style and various animation lights.(link)
Click here to find more flashlight apps for iPhone from official and third party sources.