Synchro Messenger

Send real-time overlay messages to poolside Chromebooks during artistic swimming competitions over your local network.

Synchro Messenger lets competition coordinators send real-time, full-screen overlay messages to Chromebooks and other Chrome browsers on a local network — purpose-built for artistic swimming meets. HOW IT WORKS One device runs as the sender (coordinator), while poolside devices run as receivers. Messages are relayed through a lightweight server on your local network — no internet connection required. When a message arrives on a receiver device, it appears as a large, unmissable overlay covering the screen. The operator taps anywhere to dismiss it and get back to work. FEATURES • Full-screen dismissable overlay — impossible to miss during a busy competition • Send to all receivers at once, or target a specific device • Normal and urgent message priorities with distinct audio alerts • Live device dashboard showing all connected devices, their status, IP, and platform • Message activity log with one-tap resend • Auto-reconnect if the network drops • Works entirely on your local network — no cloud, no accounts, no internet needed SETUP Run the Synchro Messenger relay server on any machine on your network Install this extension on all devices Configure each device with the server address, a device name, and its role (sender or receiver) Start messaging The relay server is a lightweight standalone binary — download it from the project's GitHub repository. No Node.js installation required. BUILT FOR COMPETITION DAY Synchro Messenger is designed for the realities of running a swim meet: quick setup, no accounts to manage, no internet dependency, and messages that simply cannot be overlooked on a busy pool deck.