The Smart Activity Tracker fills a big hole in the company's product portfolio. In fact, as far as ecosystems go amongst the likes of Fitbit, Jawbone, and Nike, Withings has the most extensive, offering Wi-Fi scales for adults and babies, a blood pressure monitor, baby video monitor, and a claimed compatibility with over 60 partner apps and devices. Fitbit, by comparison, offers a Wi-Fi scale and two clip-on fitness trackers.