Here goes all the not-so-rail-road things to do with an ESP8266:

a) Temperature and Humidity with an ESP8266 ESP-01 with a DHT11.

b) or an Arduino sketch to control a TV in a room where you just need to turn the power on and off briefly with a Sonoff, so the TV stops making a noise.
Subpages (2): DHT11 MyTV Web Server