Nice application of a esp8266. Besides helping you watch your plants die, you could also ue this to help brewing your beer:
As the fermentation process progresses, you lose weight in the form of CO2. This weight loss is also gradual (like in this plant thing), when it tapers off your beer is ready. Combine this with a onewire temperature sensor (no analog) and one or two pins to a heater or TEC unit, and you got yourself a full blown fermentation controller!