Heart Plot vs Skinfold

IMPORTANT: This app REQUIRES a Polar H10 heart rate sensor. Heart Plot is a specialized tool designed for the Polar H10 chest strap. It visualizes your heart's rhythm in real time using Lorenz (Poincaré) plotting. By measuring the precise RR intervals (the time between two heartbeats), Heart Plot maps your heart's behavior onto an X-Y plot. This shows patterns that a simple pulse reading never reveals. SEE YOUR HEART RHYTHM IN REAL TIME • Live Lorenz plot: watch the pattern grow with every beat. • Extra beats at a glance: Heart Plot estimates premature beats and sorts them into two groups, supraventricular (SVES) and ventricular (VES) extra systoles. Counts and percentages appear below the plot. • Trend chart: tap the SVES/VES values to see how often extra beats occurred per 15 minutes over the whole recording. • Capture episodes: useful for documenting an intermittent event to discuss with your doctor. • Fitness & HRV: follow your heart rate variability (RMSSD) during rest or training. • Built for endurance: from a quick check to a 24–48 hour continuous measurement. HEAR YOUR HEART Every beat of your own heart can be played as a short tick, in your real rhythm. The sound is delayed by about 2 seconds because of Bluetooth transmission and smoothing. It also works with the screen off or the app in the background, so you can follow your heartbeat by ear without looking at the display. • Optional separate beep for each detected SVES or VES. You can hear a premature beat as it happens, even when the screen can't stay on. • Beat sound and extra-beat beep can be switched on independently. For example, you can stay silent except for extra beats. KEY FEATURES • High-resolution data: every RR interval straight from the Polar H10. • Stay-Awake mode: keeps the screen on during long measurements. • Session recovery: an interrupted recording can be resumed after a connection loss or app restart. • Load & review: open a previously recorded CSV file to view its plot, HRV and extra-beat statistics. • Data export: share raw data (RR intervals, timestamps, beat classification) as a CSV file via the Apple Share Sheet for Excel, Python or R. • Free to use: no paywall. Optional tips support development. PRIVACY FIRST Your health data stays with you. Heart Plot has no accounts and no cloud servers. Measurements are stored only on your iPhone until you export or share them. MEDICAL DISCLAIMER Heart Plot is not a medical device. It is a data visualization tool for informational, educational and fitness purposes. It does not diagnose, treat, cure or prevent any condition, and it is not a substitute for an ECG or a Holter monitor. The SVES/VES detection is an estimate calculated only from the timing between heartbeats. It cannot see the shape of the ECG signal, so it can miss events, count false events and confuse the two types. Results are indicative only and must not be used for diagnosis or treatment decisions. Sound feedback is delayed and may miss or add beats; do not rely on it for monitoring in any situation where your health depends on it. Always consult a physician to interpret your data. If you feel unwell, have chest pain, dizziness or palpitations, seek medical care immediately. Do not delay or stop treatment based on this app. REQUIREMENTS • Polar H10 heart rate sensor (chest strap) • iPhone with Bluetooth

Estimate body fat percentage from three-site skinfold readings, review changes over time, and optionally add the final estimate to Apple Health. No account is required. CLEAR GUIDANCE, MILLIMETERS OR INCHES See the Jackson–Pollock three-site locations for the selected sex, together with practical measurement instructions. Switch all readings between millimeters and inches while Skinfold keeps the calculation in the same underlying units. RESULTS, LOCAL TRENDS, AND APPLE HEALTH Skinfold uses the Jackson–Pollock three-site body-density equations and the Siri equation for converting body density to body fat percentage. It also shows general reference ranges. Save a result when you choose, then review changes in local history. Separately, you can choose to add only the final body fat percentage estimate to Apple Health. Skinfold never reads HealthKit data or writes raw skinfold readings. PRIVATE AND OFFLINE No registration, ads, analytics, developer cloud sync, or tracking. Calculations and saved local history stay on your device and are not sent to the developer. Apple Health access is optional, user-initiated, and write-only. Core features, the Privacy Policy, and Support are available offline. SCOPE AND IMPORTANT INFORMATION The source equations cover men ages 18–61 and women ages 18–55; results for women over 40 should be interpreted with care. The app does not calculate an estimate when the sum of the three site averages exceeds 120 mm (4.724 in). Skinfold estimates can vary with site placement, technique, calipers, individual differences, and the limits of the equations. This app is for general fitness and personal tracking only. It is not a medical device and does not provide medical advice, diagnosis, or treatment.