The phone can monitor your pulse using the old camera-lens-as-an-optical-heart-rate-monitor trick that's been knocking around these last few years. Android users shouldn't feel left out, since they can visit the Almost Forgot website if they're rocking Lollipop or Marshmallow. As Dagan says himself, he wanted to "let the listener create their own version of the song with their heartbeat." Who knows, maybe this sort of curation will become commonplace as wearable devices get more prevalent and music playback gets smarter. We can imagine a whole new generation of artists blaming the poor reception of their next album entirely on the fact that none of us were pumping our heart hard enough to listen to it properly.