No Nonsense Twitter od Tom Panton

Clean up the appearance of Twitter
The new Twitter's a bit yucky, really. No Nonsense Twitter cleans it up by removing eyesores such as the "trends for you" section and adjusting the appearance of some other elements of the page.

Hide promoted tweets
Promoted tweets that load on your timeline will be hidden so that you will only see the content that you want to see.

Remove Twitter Analytics (mostly)
Normally, when you click a link on Twitter, you will be redirected to Twitter Analytics. This takes time and, to be honest, it's a bit creepy, so No Nonsense Twitter removes Twitter Analytics from links wherever possible. This currently only works for text links on your main timeline, but all links should be supported soon.