Broadcasting to twenty thousand phones when the network is gone
A patented live-experience platform that turns a packed venue full of phones into a coordinated second screen - synchronized light shows, live stats, exclusive content - without needing cellular or WiFi at all.
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- 1M+
- People reached
- Across live events
- None
- Network required
- Works with cellular saturated
- iOS + Android
- Platforms
- One broadcast, both natively
- 55
- Tour dates powered
- Single arena tour
The challenge
Live events are exactly where phones stop working. Twenty thousand people in one place saturate the cellular network, and venue WiFi rarely covers a crowd at that density.
That is also precisely where you would most want to do something coordinated with everyone's phone. Every conventional approach - push notifications, sockets, polling - assumes a working connection per device. At a sold-out arena, none of them survive contact with the crowd.
What we did
The insight was to stop treating the phone as something you connect to and start treating it as something that listens. Instead of thousands of individual connections, APPIX broadcasts - using Bluetooth Low Energy beacons any nearby phone can receive without pairing and without a data connection.
The broadcast format was chosen for one decisive reason: both iOS and Android receive it natively. One broadcast system reaches every phone in the venue instead of needing two.
The build split in half. A control station written in Python runs on dedicated on-site hardware and drives a network of beacons, so an operator's cue becomes a coordinated change across the whole venue in real time - which meant hard thinking about timing, RF interference, and keeping many transmitters in lock-step. On the other side, native receiver logic in Objective-C and Java scans for beacon advertisements and maps a detected signal to an in-app action: show this image, play this clip, flash this colour.
The hardware narrowed as the design settled. The control station prototyped on Raspberry Pi and shipped on BeagleBone - a pared-back board carrying what the job needed and not much else, because every unused subsystem is cost, power draw and another way to fail in a venue. The beacons went further: rather than adapt a development board, we designed a PCB around an ESP32, so what went into the field was built for this and nothing else.
Because it is a broadcast system rather than a set of connections, it keeps working when the network is completely underwater. That is the entire point.
The outcome
APPIX grew from a prototype into a distributed platform spanning mobile apps, embedded control hardware, and cloud infrastructure across DigitalOcean and AWS. It has reached over a million people.
It has powered live experiences for Disney/Pixar, the UFC, Red Bull, Universal, the Cleveland Cavaliers and the Hollywood Bowl, including a custom "UFC In Action" app and a 55-date arena tour. The technology is patented, shipped on both the App Store and Google Play, and has been covered in the tech press.
The lesson generalizes well past beacons: when you need one-to-many at scale, reach for a primitive that is already one-to-many instead of forcing a one-to-one tool to do the job.
Worth noting: this one was hand-written, start to finish. It predates AI tooling being part of how we work, and the hard parts - RF timing, keeping transmitters in lock-step, native receiver behaviour on two platforms - were solved the long way.