LapLync

No sign-up, no ads. Sync stopwatches across devices over Bluetooth, Wi-Fi, or the internet. Share a 6-digit code and tap Start.

LapLync keeps every device on the same clock — precisely.

Whether you're timing sprint drills on the sideline, running a swim meet, or coordinating a field exercise across multiple stations, LapLync starts all devices at exactly the same millisecond and keeps them together even when connectivity drops.

FOR COACHES AND TRAINERS Hand athletes their phones, share a 6-digit room code (or let them scan your QR), and tap Start. The 3-2-1 countdown fires on every screen simultaneously. Laps and splits are logged automatically — no additional hardware, no manual data entry.

FOR COMPETITION TIMEKEEPERS AND OFFICIALS Assign devices to each judge station or timing post, create a room, and every device runs in perfect sync whether they're on the same venue Wi-Fi or each using their own mobile data. Sub-50ms precision, anchored to Apple's NTP time servers.

NEVER DROPS — THREE-LAYER RESILIENCE LapLync's connection system degrades gracefully so measurement never stops: • Bluetooth + Wi-Fi (5–30ms): used first when devices share a local network • Internet via WebSocket (30–140ms): auto-switches when devices aren't on the same network • Independent mode: if all connectivity fails, each device keeps running from its NTP anchor — recordings merge automatically when the connection restores

A brief "Reconnecting…" banner appears. The stopwatch never pauses.

NO ACCOUNT REQUIRED Create a room and share the 6-character code by voice, chat, or QR scan. Participants join in seconds. No sign-up, no password, no email address. When the session ends, the room disappears.

WHAT'S INCLUDED

Free • Rooms with 2 devices — you and one more • Join any room as a participant, as often as you like • Synchronized start, lap recording, and split times • Full connectivity: local Bluetooth/Wi-Fi, internet relay, and automatic fallback • Your 3 most recent sessions, saved locally

LapLync Pro — a one-time in-app purchase • Rooms with up to 8 devices • CSV export — share via AirDrop, Mail, or any app • Unlimited session history, saved locally

Only the person who creates the room needs Pro. Joining is always included — hand a phone to anyone and they can take part. No subscription, no ads, no account.

PRIVACY FIRST LapLync uses only your device UUID and device name — to identify and label your device within a room. They are kept in temporary session state while the room is active and deleted when the session ends. No location data, no contacts, no tracking, no account.

Requires iOS 17 or later.