As one of its daily deals, Best Buy via eBay offers the Withings Pulse O2 Activity, Sleep, Heart Rate & SPO2 Tracker in Black, model no. 70031601, for $79.99 with free shipping. That's tied with our January mention as the best price we've seen. (It's a current low by $20.) It tracks steps, elevation, distance, running, calories burned, heart rate, and blood oxygen level, and features real-time coaching via the companion Health Mate app for iOS and Android. Deal ends today.