This free version of Echofon is definitely the best Twitter client on the Mac as of this review. It supports the most third party services, does so inline most of the time, and has some nice, deep features. Multiple account access is, at least.. there.
That said, Tweetbot is coming. And Mountain Lion has already launched, with nary an update from Naan studios to either this free version or their paid version. Insertion of the current Safari page remains broken since 10.8/Safari 6. Echofon still doesnt have a true conversation view (you can follow a few back-and-forth posts if you happen to catch one of the replies, often not all of the posts, but you cant do the same using the first post as a starting point). Theres no indication of being favorited, re-tweeted, anything.
The light gray design is looking a little old, but thats not a big deal. The worst design flaw of Echofon is that creating a new tweet or switching accounts is relegated to 36 pixels at the VERY BOTTOM of the window. Can anything be more awkward? In fact, yes. Try to pop up that menu to switch accounts, or just to check for notifications on those accounts. Half the time, the menu wont draw completely upwards, but will draw half-up, and half-blocked by the bottom edge of your display. You then must jiggle the cursor to get the menu to scroll up and display completely. How is this good design, ever?
Bottom line: Right now, get the free version. Or if you prefer the best monitoring of multiple accounts, stick with the now-dead official app from Twitter. With Naans lack of recent updates, theres no way Id spring for their paid version. Then give Tweetbot a look when it comes out (though Im hoping they add a few more keyboard shortcuts for those of us who dont swipe-swipe-swipe all day, you know, because this is a computer and not an iPad).
KernelG about Echofon Lite for Twitter