If you integrate Home Assistant with FreshTomato, you can track/monitor devices connected to the FreshTomato router. As of this writing, there are currently two known implementations of HA-FreshTomato integration.

First, the implementation on the Home Assistant website. See this page to learn how to configure a basic setup:

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

However, before using this, you should be aware of the large limitation this code has: Excerpted from the webpage:

This particular Tomato integration allows one to track devices which are connected to a wireless router that is running Tomato as firmware.

Because of a limitation in Tomato’s API, this integration will only track wireless devices.

This integration is confirmed to be working with FreshTomato 2020.8

The github page containing the Home Assistant source code for Tomato integration can be found here: https://github.com/home-assistant/core/tree/dev/homeassistant/components/tomato

Note that, at the time this wiki entry was written,

An alternative that may function better in many cases is ha-freshtomato https://github.com/mx5gr/ha-freshtomato