Twitter recently launched their new ads platform. One of the features of that platform is free performance analytics which allows you to see your tweets actual reach (without having to use a third-party service).
You can see how many people are clicking on the links you tweet, how many people have favorited your tweet, number of retweets, mentions and follows/unfollow. And all of the data can be exported as a CSV file!
To access it, just go to ads.twitter.com, sign in with your Twitter credentials then click on the ‘Analytics’ menu item.