Tagga®

A user model with friends, groups and history — the shape every competitor has. A hybrid where sessions are optional inside a profile.

Every real use I observed was bounded: a ride, a hike, a festival day. Modelling the bounded thing directly removed sign-up, contacts, permissions dialogues and the privacy question in one move. A session has a start, a code, participants and an end. That's the whole data model.

No retention loop that doesn't depend on someone starting a new session. No monetisable profile. Recurring crews re-enter a code every Sunday — a friction I chose over an account and still hear about.

Phone-number sign-up with contact sync. Magic-link email. Apple / Google SSO. A QR code on the organiser's screen.

A crew forms at a petrol station with gloves on. Anything slower than reading five letters aloud loses the group. Five letters from a 30-character set give 24 million codes — enough that collisions within a live window never happened. QR lost because it needs two phones face-to-face; a code works over an intercom.

No persistent identity: no ride history, no friends list, no push re-engagement. Retention has to be earned by the next ride, not by a notification.

Name labels. Avatars. Initials in a coloured disc — the default in every location app.

At 90 km/h the question is never "who is that" — crews know each other. It's "is the group moving, and which way." A chevron that rotates with heading and stretches with speed answers both in one glyph, and stays legible at 24px in direct sun where an initial does not.

At a festival with twelve people, markers are indistinguishable. I added a long-press to reveal the name — a second interaction I'd rather not have — and a colour per rider, which capped comfortable group size at eight.

Hide the marker on signal loss. Keep the last known position as-is. Show a "last seen 2 min" label next to it.

A hidden marker reads as "they left". A frozen one reads as "they crashed". A label needs reading. Fading the marker in three steps — 30 s, 2 min, 5 min — puts uncertainty in the same visual channel as position, so it's understood at the same glance.

Three extra states on every marker, across three platforms. And a rider fading out in a tunnel still triggers a worried phone call — the design communicates uncertainty; it can't remove it.