Mac users can use the native Micro.blog for Mac app. It’s a free download and supports most of the same features as the iOS version.
You can see a short video of it on Manton's blog. You'll even notice a rather handsome avatar make an appearance.
Unfortunately I cannot give this a spin yet since I haven't upgraded my Mac to High Sierra. And it doesn't appear I'll be doing so for at least a month or two since I haven't seen any updates from Apple on that front. High Sierra just seems far too unstable to switch to on my main work computer at the moment.
Colin Walker, though, seems to like this new app:
Manton has repeatedly said that this is just a version 1.0 app but, I have to say, it’s been rock solid. Browsing, replying and posting to the blog have all been a breeze and I’ve not had a single issue or error.