The Knut is a Wi-Fi enabled, battery-powered sensor-hub that can be used to monitor temperature, opening of doors, humidity, vibrations and much more. The device can then alert you of any changes directly to your mobile phone. Check out their Kickstarter page.
Knut has a high accuracy temperature sensor and a battery level sensor built in. If you want to monitor more than just temperature, you can connect an external sensor or multiple sensors using the 3-port hub. Currently we have functional humidity, vibration, door, water proof temperature, and water presence sensors.