This one is no brainer..
It has got to be the eSteem app for sure.
I just love it's so many features including post scheduling, drafts, it's easy interface and the ease with which I can easily edit and structure my post using the app just to name a few. It is a fascinating app and to top it all, it's users reward system is great. With all these features embedded in the app, one still gets rewarded for using the app. What more can I ask for?
It's so amazing and it has really changed my steem experience in a massive way.