Trying to catch up on "House of Cards" before your friends spoil it for you? You might end up watching late into the night — and possibly dozing off during a quiet section. Fortunately, an experimental feature from Netflix uses your fitness tracker to tell if you've fallen asleep, so you can pick up where you left off later.
It works by tracking the data put out by a FitBit device, which you can OK to be used by the Netflix app (at least, in this special version of it). When it detects that you've fallen asleep — the FitBit has ways of knowing — the screen slowly fades to black and a bookmark is created in the show.
The next day, when you wake up in the living room with half a bowl of popcorn in your lap and try to remember what episode you dozed off in, you'll find the show has a "sleep bookmark" from which you can resume. Get back to watching!
Unfortunately, you can't actually get this feature for your set-top box. Sleep tracking was just a fun idea concocted by Netflix engineers for the company's Hack Day and posted by the company on their blog — along with a few other ideas, some of which also look pretty handy.