I’m a big fan of Fitbit, the wearable activity tracking devices. I’ve got the Fitbit Flex which tracks your activity (mostly how far you walk) and sleep. And I’ve got the Aria scale, which is a Wi-Fi enabled smart scale.
Things you can measure you tend to optimise to. And having smart devices tracking my activity is a really easy, passive way to engage with a part of my life that I otherwise don’t focus on much!