Loupe demonstrates the device-fingerprinting signals iOS apps can read

Category: Apple
Status: discussion
Sources: mysk-research/loupe, discussion
Summary: Mysk published Loupe, an iOS and iPadOS app (MIT-licensed source) that displays the data a native app can read to fingerprint a device. It groups the signals into passive ones needing no permission (locale, time zone, screen details, battery status), permission-gated ones (contacts, photos, location, calendars), and advanced side channels such as URL-scheme probing and Keychain persistence. The project notes the app was written almost entirely with AI coding tools. The thread led the HN front page (428 points).
Why it matters: It makes concrete how much entropy an installed iOS app can gather without explicit permission prompts, relevant to developers reasoning about tracking and consent surfaces on Apple platforms.