10 Apps That Will Turn Your Apple Watch Into a Sleep Tracker

Cost: free to download; membership is $5 per month after a seven-day free trial

A sleep app won't do you any good if you have trouble falling asleep, so if you consider yourself an insomniac, download Better Sleep. This app tracks your sleeping habits; uses them to calculate your ideal bedtime; and has a library of guided meditations, bedtime stories, and sleep-inducing isochronic tones to help you fall and stay asleep.