SPIN needs to be run on a gateway system, so either a router, or a local access point for a subnet. It consists of two daemons: the traffic collector daemon spind, and the web interface spin_webui. SPIN also requires an MQTT server available to both, with mqtt open on port 1884 and websockets support on port 1883.
When using a Valibox installation, all of this is started automatically.
For more detailed information, see the README on github.