Hi,
This is a couple of years old... but I wanted to present my ESPWidget project (https://github.com/joewez/ESP-Widget) in case it gives somebody an idea.
It's basically a Wemos D1 Mini connected to about as many simple devices as I could... an OLED display, a NeoPixel, a piezo buzzer and three user buttons.... stuffed into a 3d printed case. It initializes into an AP, where the normal Wifi parameters can be set, and then periodically checks for a specific file that it uses to update the device.
There is a feeder piece that generates the display files, but that was separate from the actual ESPWidget. The test implementation I used was a web-scrapping Windows app that collected data from a traffic website and presented the info on the widget.
Anyway the point of the device was to be a monitor for data and events that could be pulled together by another process. What that data is, is totally dependent on the feed application.