Meet the BLUEmometer: a smart thermometer that pairs with your smartphone via Bluetooth to provide you with instant temperature data. Since it is hermetically sealed, you can use it to measure the temperature of liquids. It can be used to measure the temperature of pool water, baby milk, and other liquids. You can set up an alert to get notified when your liquid has reached the right temperature.
The BLUEmometer has a battery that lasts up to 10,000 temperature measures. The product is compact and portable. It is food friendly too. You can find it on Kickstarter.