Integrating Home Assistant with FreshTomato allows you to track devices connected to a wireless router running FreshTomato firmware.

See this Home Assistant article for an example of how to configure a basic setup:

https://www.home-assistant.io/integrations/tomato/

This github page contains the Home Assistant source code relating to Tomato integration: https://github.com/home-assistant/core/tree/dev/homeassistant/components/tomato