Looking at Fitbit’s sales numbers and especially growth rate (or lack thereof) in an otherwise booming wearable device industry these last few years, you might be wondering why Google is so keen to spend $2.1 billion on acquiring the 2007-founded American company. But it’s important to remember we’re talking about a pioneer of the activity tracker market here, and in many ways, Fitbit has managed to stay well ahead of the rapidly improving competition all these years.

If you’re lucky, all you need to do to get a cool new graph in your Fitbit app is, well, update said app to its latest version. The graph will show you fluctuations of your blood oxygen saturation level detected while you sleep, focusing on “big variations” that could reflect serious breathing issues. Of course, you shouldn’t rely entirely on this data “estimated” by your Fitbit to self-diagnose disorders like sleep apnea, and instead seek medical attention if you do notice many big variations reported frequently.