Treadwell: Treadmill Tracker

Your treadmill said 5 miles. You actually ran 4 miles, and your watch said something else entirely. You'd never have known. A treadmill doesn't measure your speed. The display shows the number it was told to hit, from motor RPM and an assumed belt size. Belt slip, wear, and drift push your real speed off that number, and the belt slows a touch every time your foot lands. So the "6.0" you're staring at is really a guess, and your watch just copies it. Treadwell measures the belt itself. Hold your phone steady over the running belt for a few seconds. Using the camera and the LiDAR sensor on your iPhone Pro, the app watches the belt surface move and works out how fast it's actually traveling, then shows you your true pace and distance. WHAT YOU GET • Quick Measure: point, hold for a few seconds, get your real speed and pace. Tell it what your treadmill is set to and it shows you exactly how far off that number is. • Calibrate a treadmill: measure a few points once, and the app learns that specific machine. After that it tells you the true speed for any setting on the display, or which setting to dial in to hit a target pace. • Workout mode: lock in your measured speed and let the app track your time, distance, and pace for the run, with pause, resume, and change-pace on the fly. BUILT HONEST This app would rather tell you nothing than tell you a wrong number. If it can't get a clean read (bad angle, belt out of frame, phone not steady) it says so and asks you to try again. It never invents a number to fill the gap. So when it gives you a pace, you can trust it. WHO IT'S FOR Runners who train on a treadmill and want to know what they actually ran. If you've ever finished a "tempo run" wondering whether you really hit the pace, or watched the treadmill pile up more miles than your legs felt, this is for you. REQUIREMENTS Treadwell needs the LiDAR sensor, so it requires an iPhone Pro or Pro Max (iPhone 12 Pro or later). Best results on recent Pro models. iPhone only. The camera reads your treadmill belt's logo or markings as they pass, so it needs a belt with something visible on it. Nearly every gym treadmill has one; some plain home belts don't. Measuring works best at your usual running speed. One safety note: step to the side of the belt to measure. Never stand on a moving belt to hold your phone.