I've loved Medium for a long time - in fact I still hear from people (other authors wanting to link/interview me, prospective clients, etc.) every singe month directly from my very first Medium post.
Medium on mobile is...so-so. Much better than the original app, but the nature of a content network means there's a ton to fit on a small screen's UX.
My only real issue with the app is the writing interface (which should be Medium's strongest point if the website is any indication). It's reminiscent of the beloved Medium writing interface, but some of the features
I've used many blog editors out there, and none has proven to be as easy and user friendly as Medium.