The Koubachi Wi-Fi Plant Sensor looks sort of like an upside down, fat-headed golf club: you stick the handle into the soil in a plant pot. It’s loaded with sensors to figure out moisture, sunlight, and surrounding temperature. A Wi-Fi radio connects to your home network and sends the data to Koubachi’s servers, accessed via a native iOS app. It’s priced at about $162. You only need to buy one: just keep moving it from one plant to the next every couple of weeks to collect data for the server.