What you want sounds like it can be done with the "Attribute" tile, which lets you use any custom (or stock) attribute and display its value on that Dashboard tile. If you choose a string attribute that you're capable of manipulating from an app/rule/piston, then that should work. A Virtual Omni Sensor device has a "variable" attribute you can set to whatever you want, which would work if no other device you already have seems more appropriate for this, but that's just one a few options you can probably find (an RM string global variable connector would be another, even if you don't use RM for anything else).
Download the Hubitat app
