The top maker of fitness trackers took a small step forward with an update to its tiny Alta. The updated Alta HR adds heart rate tracking to the device, which is small enough to fit inside a variety of bands and other jewelry-like holders. The Alta previously was useful mainly for tracking steps, sleep, and offering the occasional notification alert from a linked phone. The addition of heart rate tracking makes the band more useful for exercise and more comparable to Fitbit’s Blaze and Charge 2 trackers. The Alta HR will ship next month and cost $150-$20 more than the original.