Up to 100 million users downloaded a popular Android app that turned their phones into flashlights. What they didn’t realize was that their smartphones also became sophisticated tracking devices, with the app collecting information that could pinpoint their precise location. The Federal Trade Commission on Thursday issued its first enforcement action related to location-based technology, reaching a settlement with the maker of Brightest Flashlight Free for allegedly hiding the fact that it sold information about the location of its users and the unique string of numbers assigned to a device. The free flashlight app deceived users by indicating that the data would be used only for internal purposes, the FTC said. It also gave users the fake option to refuse location tracking, collecting and sharing the data with third parties regardless of a consumer’s choice, according to the agency.