Mute not working?

I downloaded this client was because it has a "mute" function, and because it has a one-column view similar to the native Twitter client and to Tweetbot on my iPhone. However, the MUTE feature doesnt seem to be working. I cant find any help on the app or web site to ask about this feature.

The interface is hard to read, its difficult to customize, and its operations are counter-intuitive.

Im deleting this app. I can hardly wait for Tweetbot to come up with a desktop client.

vic_toria about Night Owl, v2.74