Jawbone's UP bracelets are different from other fitness trackers. Unlike the Fitbit Flex and Nike FuelBand, Jawbone's UP bands don't have small screens on them, which means you can't glance down and look at how many calories you've burned, check the time, or see if you've missed any calls. But, according to one Jawbone executive, that's part of what makes the Jawbone platform work so well.