dokuda

it's the same thing I could do with a notepad and a pen on the nightstand.

I think you might have misunderstood the sleep tracking feature. It also tracks when you're awake or restless while you're sleeping so you can understand if you slept well or not.

Last time I checked, my notepad and pen didn't do that.

The other nice thing is that there's no requirement to sign up for anything. You can view all the lessons here:

http://hackdesign.org/courses

I recommend http://hackdesign.org/

They have collections of resources and articles curated by web designers and front-end developers focusing on user interfaces and design theories.

These aren't tutorials, but materials for you to read, learn, and apply to your designs and interfaces.

If you don't have Photoshop, there's a free app that let's you simulate your screen with 3 different forms of colorblindness.

http://colororacle.org/