Magnetometer vs WatchWatcher

Magnetometer is a fun app for finding metal or magnets by detecting EMF interference with your iPhone's compass heading. Find your keys, or just have fun discovering what could be made of metal. Magnetometer is not meant to replace an actual, professional-grade metal detector. Magnetometer presents simple information to the user about the interference experiences. For more scientific data, please turn to other great apps on the App Store. Magnetometer is made for fun and for experimental purposes and is not designed for scientific use. Also, don't drop your iPhone in sand hoping to find treasure; it's risky.

Enhanced App Store Description The most complete, precise, and effortless way to track your watch’s accuracy over time. Whether you’re a casual owner or a serious collector, WatchWatcher helps you understand exactly how your timepieces are performing—day after day, week after week. Powerful timing tools • Add timing events in two ways: a simple manual tap or automatic extraction from an image. • Reset your watch to an accurate reference time and continue tracking seamlessly—the app can recalculate all past events with a single instruction. • View a beautiful, full-size graph in your browser showing all your watches at once. Insightful accuracy data • Switch between absolute difference and rate drift to see your watch’s behaviour from every angle. • Discover how your watch compares to others—both across all users and within its specific brand. • See average drift across all time, or focus only on the most recent two events. Smart predictions that save time • When you log a new event, WatchWatcher predicts where your watch should be based on historical drift—minimising adjustments and speeding up logging. • Fine-tune prediction behaviour in settings for even more accuracy. Import, export, and stay in control • Easily back up or migrate your data with iCloud import/export or CSV. • All online features work without creating an account. • No subscriptions, no in-app purchases—just powerful watch-tracking tools, free and private.