What is TenSync?

TenSync is a minimal timing game. Tap START, then tap STOP at exactly 10.00 seconds. The closer you are, the higher your accuracy.

The twist: when other iPhones running TenSync are on the same Wi-Fi network, they automatically discover each other and start every round at the exact same moment, synchronized within ±2 ms. Each device measures its own STOP independently. Race friends in the same room with no setup, no accounts, no servers.

How to play

1. Tap START to begin. The timer starts immediately.
2. When you think 10 seconds have passed, tap STOP. Both buttons fire on touch-down (no release-delay).
3. You see your elapsed time, the deviation from 10.00s, and an accuracy percentage.
4. If you do not stop within 11 seconds, the round ends as FAILED.
5. Tap RETRY to play again.

Sync mode

If other iPhones running TenSync are on the same Wi-Fi, the header shows a Wi-Fi icon and a peer count. When connected:

• Tapping START on any device broadcasts a synchronized start. All connected devices begin the round about 0.5 seconds later, at the exact same instant.
• Each device's STOP is measured independently. Results are not shared between devices.
• iOS will ask for "Local Network" permission on first launch. Allow it for sync to work.

Tick sound

An optional tick fires every 1 second while running, with a downbeat at t=0, to help you stay in rhythm. Toggle it in Settings. The hardware silent switch always silences it.

Best score

The smallest absolute deviation across all your attempts is shown in the header as BEST x.xx. Failed rounds and ties do not update Best. Best is stored locally on your device.

Privacy

TenSync uses Firebase (Analytics + Crashlytics) for anonymized usage and crash diagnostics. No ads, no advertising identifiers, no tracking. See the Privacy Policy for details. We do not collect personal information, do not store data on our servers, and do not require an account.

Contact

Email: hirose@hakaru.net