HRV vs Critter

HRV Tracker — private, on-device insights from your iPhone and Apple Watch. Turn heart-rate variability, heart rate, sleep and activity data from Apple Health into clear views of stress, recovery and energy. Track both SDNN and RMSSD, calculated from available beat-to-beat intervals. iPHONE APP • Home dashboard for HRV, Recovery, Sleep Score, Stress, Energy, Activity, heart rate and weight • Today view comparing your day so far with your usual pattern at the same hour • Detailed HRV, Sleep, Activity, Strain and Weight views • Behaviour logging for habits such as alcohol and caffeine • Daily and weekly coaching • Interactive daily, weekly, monthly and yearly charts PERSONAL INSIGHTS Explore which parts of your routine are associated with changes in HRV, sleep, stress and other measurements. • Influences screened against chance • Stronger findings separated from preliminary and descriptive patterns • Combined effects for pairs of behaviours • “Moving Together” comparisons between health metrics • U-shaped relationships • “Compare Everything” matrix and influence explorer • Personal experiments in Labs Insights describe associations; they do not prove cause and effect. TODAY & COACH Compare today’s readings with similar hours from your history. Coaching can consider sleep, recovery, stress, energy, activity and events such as workouts, late coffee or mindfulness. A separate note summarizes the previous seven days. AI-written coaching requires an Apple Intelligence-compatible iPhone running iOS 26 or later, with Apple Intelligence enabled and available for your device language. Other devices retain their scores, insights and standard app-written coaching summaries. Coaching is generated locally; health information is not sent to an external AI service. KEY SCORES Stress — A continuous 0–100 physiological-load score. When both signals are available, it combines 40% HRV with 60% heart rate. It continues with heart rate alone when no nearby RMSSD exists. The curve shades sleep, excludes workouts and identifies missing watch periods. Stress reflects physiological activation, not emotional stress. Energy — An all-day 0–100 estimate of how much you have “in the tank.” It recharges during sleep, taking Sleep Score and sleep stages into account, and responds to calm, stress and physical effort. Compare it with your usual reserve at the same time. Sleep Score — A nightly 0–100 score blending duration (35%), continuity (25%) and restfulness (40%). Restfulness considers overnight HRV, heart rate and physiological load. Scores personalize as your history grows. Recovery — Compares RMSSD with your history at a similar time of day. iPhone uses up to 30 previous days without including a reading in its own reference. Apple Watch uses a shorter local history, so its quick score may differ. Activity — Combines movement with sustained effort. Workout load uses heart rate when enough readings are available; otherwise it is estimated from workout type and duration, so yoga is not treated like intense cardio. The Activity page shows what contributed to the score. APPLE WATCH • Native Recovery and Stress views • SDNN and RMSSD at a glance • Stress and HRV charts • Complications and widgets • RMSSD from available heartbeat series • Support for dense chest-strap readings • Cached baseline for faster opening DATA & PRIVACY HRV Tracker analyzes Apple Health data on your devices. Your health history is not uploaded to an HRV Tracker server. AFib History on a compatible Apple Watch greatly increases beat-to-beat sampling and is strongly recommended for complete RMSSD, Stress, Energy and Recovery views. With infrequent measurements, some curves and insights may remain incomplete. HRV Tracker is intended for personal information and wellness. It is not a medical device and does not diagnose or treat any condition.

Critter Counter is the simplest way to keep score of the animals (and anything else) you spot on a walk. Tap once for every critter you see. We'll quietly log the time and location of each sighting so you can revisit the walk later, see exactly where you spotted what, how many you found, and how long you were out. Track one animal or twenty. Rabbits, squirrels, hawks, frogs, neighborhood cats, mushrooms, cool rocks... whatever you want to notice, Critter Counter will count it. Whether you're on a slow evening stroll, a morning loop through the park, or a backyard wander at dusk, Critter Counter turns noticing into a tiny, joyful ritual. FEATURES • Count anything: Start with the twenty common animals we ship with, or add your own. Rabbits, squirrels, owls, butterflies, or "the weird heron at the pond." It's your list. • One-tap counters: A big, satisfying button for each thing you're tracking. No menus, no fuss. See it, tap it. • Sighting map: Every tap is pinned to where you were standing. Review your route as a map of small moments. • Walk history: Every walk is saved with its totals, duration, and sightings. Scroll back through every evening you've been out. • Apple Watch companion: Leave your phone in your pocket. Count from your wrist while you walk, even with multiple critters tracked at once. • A calm design: Dark-mode-friendly so it won't blast your eyes after sundown. • Undo a tap: Accidentally double-counted? One button removes the most recent sighting. • Guest mode: Don't want an account? Use the app without signing in. Your walks stay on your device. • Optional sync: Sign in with a magic link (no password) to back up your walks and sync between iPhone and Apple Watch. WHY USE IT Most fitness apps care about your pace and heart rate. Critter Counter cares about what you noticed. It's a small, single-purpose app for people who pay attention to the world around them and want a record of the small wonders they've crossed paths with. Great for: • Daily dog walkers • Suburban evening strollers • Birders, naturalists, and backyard observers • Kids learning to notice wildlife • Anyone who finds animals delightful (so, everyone) PRIVACY Your location is used only to tag your sightings and draw your walk on a map. In guest mode, nothing leaves your device. If you sign in, your walks sync securely so you can see them on any device you're signed in on. We never sell your data and we don't show ads. You can delete your account and all of your data from inside the app at any time. Happy spotting!