There are plenty of devices you can use to quantify your life, from free apps to expensive gadgets. Here is a short list to get you started.
Health: iHealth makes glucometers, blood pressure monitors, and oximeters.
Fitness: wearables like Fitbits and Apple watches are the most popular fitness trackers.
Sleep: try SleepCycle or Sleep as Android to track sleep quality and duration.
Productivity: download RescueTime on your computer to find out how much you procrastinate.
Environment: check out home weather stations like Netatmo, Foobot and Awair