Thermodo: €32

Ever have the burning need to know exactly how warm/cold it is? A temperature gauge in the palm of your hand, Thermodo can help with that. The mini device, which is made from scratchproof aluminium, connects with your smartphone and can be attached to a keychain so you have it on hand for those temperature related emergencies.

Thermodo plugs into the audio jack on your smartphone, that useful little port that has been wasted for years on simple headphones. Best of all, it works with both Android and iOS devices, including your iPad, so no one gets left out.

firebox.com