Parrot Flower Power
We bought this about 18 months ago for about £45. You put this device into a pot with your favourite plant and it monitors the environment so you can keep your plant healthy (indoors or outdoors).
One AAA battery will last the device 6 months or more and connects to an app on my iPhone via Bluetooth.
It is able to monitor how much light the plant is getting, temperature, level of fertilizer, soil moisture content and displays the statistics for you in real time and logs the history for you. The app has a database of plants and their ideal environment so you can check your plant against these and keep it healthy.
Paul Clews 