You don’t need a specialized fitness monitor to track how far you walk each day. Step and activity tracking apps are multiplying to take advantage of movement sensors already inside smartphones. But can these free apps track step counts as well as a $99 bracelet monitor?
Yes, according to a new study published in JAMA. With more than half of Americans carrying smartphones—versus about 1 percent wearing specialized activity trackers such as those made by Fitbit or Jawbone—researchers think tapping into these apps could help many more people get active.