Something that my laptop doesn't have is a WiFi-activity indicator. It has LEDs for Ethernet, yet not for WiFi.
That problem is rather simple to solve!
To get around the missing WiFi-activity indicator problem, all you need is an ESP8266 like the WeMos D1 and some software.
The software is really simple: it enables "promiscuous mode" for WiFi and then blinks the built-in LED when a packet is received. Add some frequency-hopping and you're done.
Download link for the Arduino sketch (the ZIP-file includes a platformio build script): wifi-activity.zip.
This can be improved by:
- selecting of a channel to listen on (now picks randomly one every 250ms)
- selection of a MAC address to listen for