Mobile · React Native · Firebase· in progress
The Helmet Signal
A mobile group-rallying app. Light a beacon, set a minimum headcount and a timer, and the clan responds in real time. Medieval-tactical aesthetic on top of modern serverless infra. Currently in security review for the app stores.

What it is
Users belong to clans of up to 50 members. Any member can light a signal: a short message, a minimum number of yes-responses needed, a maximum cap, and a timer. The whole clan gets a push notification. People tap Yes or No. The signal succeeds the moment the minimum is hit and fails the moment the timer expires without it.
That is the entire mechanic. The rest is the UX scaffolding around making it feel fast, social, and worth opening when the push hits.
Where the idea came from
About ten years ago, OpenAI was training a system that learned to win Dota 2 by getting good at the coordination mechanics. Five agents pinging the map and rallying to objectives faster than humans could. I was watching that and thinking about how much of what we ping each other for in real life looks the same: pickup basketball, weekend plans, the friend group trying to assemble for dinner on Friday at 7. We mostly do it badly. Group chats degrade into one person trying to herd cats over forty messages.
The Helmet Signal is the version of that with the mechanic borrowed from games: a clear ask, a quorum, a clock, and one tap to respond. I sketched it a decade ago and never built it. Now I have, mostly because the modern stack (Expo, Firebase, Zustand) made it a reasonable evening project rather than a six-month one.
The happy path
The core loop is three taps. Open your clan, light the signal, and watch the responses land until the quorum is met. Here is that path end to end:
The only unhappy branch is the timer: miss the minimum before the clock runs out and the signal just goes dark, no guilt and no forty-message group chat. The real in-app screens (clan list, signal creation, the live attendee feed) will replace these once the iOS build clears review and I can capture them.
Architecture
Standard small-team mobile stack:
- React Native + Expo Router for the app shell and navigation.
- Firebase Auth for email/password.
- Firestore for real-time data: clans, signals, responses. Security rules enforce membership and rate limits.
- Cloud Functions for the bits that have to be trusted: signal-state transitions, threshold detection, push notification fan-out, scheduled timer expiration.
- Firebase Cloud Messaging for push.
- Zustand for the client-side state that wraps the Firestore listeners.
Nothing exotic. The interesting engineering is in the small set of places where the real-time response counts have to be authoritative (which lives in a cloud function), and in the rules that prevent a single bad actor from flooding their clan with junk signals.
Status
MVP is functionally complete and is going through security review for the iOS and Android app stores. Real device screenshots (the functional UI, not the hero art) will land here once it ships. Public link follows.