Multi-Device Lap Scanning at the Finish Line
Mile day, 60 kids, one lap line, one phone. The fast runners are coming through three at a time and you're trying to scan QR cards before they peel off to the water table. By lap 4, you've missed a few. By lap 8, you've miscounted a few. Welcome to PE.
Today, you can pair as many phones as you have hands — or other teachers, parent volunteers, an aide — at the finish line, and they all scan into the same run. No double-counts, no missing laps, no lap-line bottleneck.
How it works
One phone is the host. Others join with a 6-digit code.
1Host phone: Pick a group, check the Multi-device mode box. A 6-digit code appears immediately. Read it out loud, screenshot it, hold it up — whatever's easiest.
2Other phones: On the home screen, tap Join multi-device run and type the 6 digits. The scanner opens with the right group already selected and the timer in sync with the host.
3Host phone: Tap Start Run. The timer starts on every paired phone at the same instant. Now everyone scans.
Why it doesn't double-count
The obvious worry: two teachers both standing at the finish line, both scanning the same kid as he goes by. Does that count as two laps?
No. The server collapses scans of the same student within 3 seconds into one lap, regardless of which phone they came from. That's the dedupe window — wide enough to absorb human reaction lag and network jitter, narrow enough that a fast runner's legitimate consecutive laps still count.
You can also adjust the per-device cooldown (how long before the same QR code can be re-scanned by your own phone) in Settings → Scan cooldown. The default is 20 seconds, which works for typical PE laps. Faster laps (track day, sprint relays)? Drop it to 10. Younger kids who hold the card up too long? Bump to 30.
What stays in sync — and what doesn't
Honest tradeoffs, since teachers ask:
When to use it
Mile day. The classic case. Two teachers at the finish, one tracking the lead pack, one tracking the kids who lap the field once or twice. No more "did you get him?" cross-talk.
Field day or relay events. Kids running through a finish in clusters of 3–4. One phone can't scan that fast. Two or three can.
Big classes. A 90-kid combined class is a lot to scan with one phone, especially when the line backs up. Pair phones at two stations and let kids fan out.
You forgot your phone in the gym. Less glamorous but real — if your aide has a phone and you don't, they can run the run.
Cost
Multi-device is included on every Running Kiddos plan, including the free tier. No add-on, no per-device fee. As many phones as you have, however many teachers want to help.
Try Multi-Device Scanning
Pair phones at the finish line, scan into the same run, and stop missing laps. Free 14-day trial, no credit card required.
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