A couple of features I would love to see:
An option to show real names instead of weird usernames
Image and video previews on timeline
Number of new tweets on the navigation bar inside the red dot
Other than that there isn't anything missing for this to become a real alternative to metrotwit, keep up the good work :)
We do have image and video previews for some image hosts and for youtube videos. I will note your other feature requests, thanks for the ideas!
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