Project
Chrono
I built Chrono, a multi-team countdown app for competitions and workshops. Run timers locally in one browser or share a session so participants can follow the same clocks live.
Public app · no account
Running a session
Each team has its own timer
Start, pause, finish and reset teams independently, add or remove time, and adjust timer speed.
Local or shared
Local mode runs without a server connection once the app is loaded. Shared sessions have a link for viewers, with controls assigned to the owner and admins or opened to everyone.
Prepare teams and keep results
Import teams and base time from CSV, export results and consult a session action log.
How shared clocks workExpand technical detailsCollapse technical details
- React and TypeScript in the browser; Express and Socket.IO for shared sessions. The server owns the shared clocks and broadcasts their state to connected participants.
Keeping your results
- Shared sessions are kept in server memory and end when the server restarts. Export results you want to keep. Following a shared session requires a network connection.
Stack
- TypeScript
- React
- Socket.IO