f.lux - I installed it has two weeks, it was for great to my eyes
Caffeine - I've used to app once my first Macbook White.
Alfred - I never liked to Spotlight, even after Apple updates on Sierra, the Alfred is so much better.
Bear - Month ago, I was use to Evernote for my notes, Apple updated Notes (on Sierra again ;) and I moved it. A week ago, I discovered Bear, I don't know where I found it, but I am using to app and I recommend for all.