Plank Timer: Core & Form Check

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Everyone
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Everyone
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About this app

Turn boring plank holds into a "keep your form" game. Place your phone on your lower back (or in your pocket) and the accelerometer detects posture breaks instantly.

◆ Real-Time Sag Detection
・Calibrate once in proper plank position before starting
・Monitors tilt; instant beep, vibration, and red flash when hips drop or butt rises
・Counts only "perfect form" seconds as valid time. Cheating seconds are excluded

◆ Form Quality Summary
・Shows best time plus break count and hold rate (%)
・Review break moments via waveform to see where form failed

◆ Records, Bests & Streaks
・Update personal bests with net hold time; track daily streaks
・Screen stays on during training; zero fullscreen ads
・Adjust sensitivity from lenient to strict

Honest note: This is a placement-dependent basic check, not medical-grade. Auto-switches to stopwatch if phone can't be placed on lower back. Fully offline, on-device processing, no data sent externally (privacy-safe).
Counts only perfect form. Instant beep/vibe on sag. Track hold rate & streaks.
Updated on
Jul 18, 2026

Data safety

Safety starts with understanding how developers collect and share your data. Data privacy and security practices may vary based on your use, region, and age. The developer provided this information and may update it over time.
  • No data shared with third parties
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  • No data collected
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