[UPDATE] Nevermind. I found it in your Hubitat Github repository. It has already found two of my devices that had issues which I have now corrected.
Just curious if you’ve posted a Hubitat version of your Device Monitor app yet?
Thanks,
Dan
[UPDATE] For others looking for a simple App to monitor your devices to see if they've gone inactive or have low battery levels, @ericm's Device Monitor App is very convenient.