How To Add Your Micro.blog Feed to NetNewsWire
Figure out the URL. It’s something like this, where my username is replaced with your username:
In NetNewsWire, hit cmd-N. (Or click the + button in the toolbar.) Put that URL in the URL field in the sheet that appears. Give it a name if you want, and choose a folder if you want. Then click the Add button.
Posting to Micro.blog
If you have the Micro.blog app on your Mac, you can select an article in NetNewsWire, then pull down the share menu in the toolbar, and choose Micro.blog.
It will send that article to the Micro.blog app, where you can edit and comment before posting.
The same thing works for MarsEdit, so you can post to any blog.