Currently to see the various sleep stages (Deep, REM, Light, Awake) you have to click each one. It would be much more helpful to see them in a combined view with the colors laid over the sleep graph. Oura does this already, btw. I’m not a super huge fan of how Oura lays it out, though.
I also think this would be useful in looking at the workout heart rate zones, same problem - you have to click each zone to see.
This would be a very simple win from a User Experience standpoint.