Shared Counter is the simple and effective tool for counting visitors to events, local businesses, religious functions and much more, even with multiple entrances.
To begin, create a new counter, optionally specifying the capacity. You can then share the counter with other devices, for example to monitor multiple entrances at the same time, via a simple link or QR code. You will always have under control the total count of all devices, synchronized in real time.
The service was created in particular for monitoring access to the churches, but is now freely available. If you are in charge of a church you can access the "Reserved area for churches", to benefit from usage statistics and other useful services on the DinDonDan Web Services.
Shared Counter is an open source project offered and maintained by the DinDonDan App association.