Monitor the State of Add-Ons in the Front End

I would like to be able to monitor the state of an add-on in the front end. It seems like this could be done with the Rest API from other posts, however, I can’t seem to find the right config. Has any one sucessfully pulled the on/off running/not running state into a sensor in the front end?

That post seems to imply its possible, however, I can’t seem to get a rest sensor to pull the info.