I'm surprised nobody's brought up @good-karma yet. He makes the eSteem app, which everyone with a smartphone is either already using or should be using. His blog chronicles the changes in the app and let's you know the differences version to version.
This comment was written in eSteem, as it's my primary method of browsing steemit nowadays.
Agree with you @good-karma
There are a lot of good people to follow here, but @good-karma is the only one I can think of that everyone should follow.