Apple promotes strong privacy protections for the iPhone, often highlighting these features during product launches. Yet many users remain unaware of the routine device information that third-party apps can access through standard system interfaces.

Security researchers at Mysk have released Loupe: What Apps Can See, a free application for iPhone and iPad. The tool illustrates the range of information that apps can obtain via public iOS APIs. It is listed in the App Store under Developer Tools and requires iOS 17 or newer.

Loupe explains common data exposure rather than tracking specific apps

The application does not monitor real-time activity of apps such as Instagram or TikTok. Instead it demonstrates the types of device signals that any developer can retrieve using the same public APIs. Users receive an interactive overview of how details like language settings, time zone, screen dimensions, battery level, storage capacity, and keyboard preferences can combine to form a unique device profile.

These ordinary attributes allow apps and websites to recognize a device across sessions even without access to personal identifiers such as names or email addresses. The combination of small signals often proves sufficient for fingerprinting purposes.

Information is grouped into clear categories

Loupe organizes its findings into three main sections. Passive signals appear without any permission request and include locale, time zone, screen properties, and battery status. The Needs Permission section covers data that prompts an iOS alert, such as contacts, photos, location, and calendars. Advanced techniques cover methods like URL scheme checks and data stored in the Keychain that can survive app deletion.

The listing also notes additional examples including detection of installed apps, the precise time a device was first activated, graphics rendering tests performed through an embedded browser view, and the name of a connected accessory that may directly identify the owner. Prior research from the same team has highlighted other privacy concerns, and this new tool further illustrates how readily available such information remains.