Improve plus sign in app

From Melissa Arnett on 2016/02/10 14:52:32 +0000

The plus sign in the app should be associated to the screen you’re on. If you’re on the sleep screen, the plus sign should add a sleep, not an alarm. Also when adding a sleep, the app could tell you which days you’re missing sleeps and ask to auto fill with you typical sleep cycle on those days.

Copied from original feature request: