Official Tweet Button for sharing articles on websites and counting how many times a URL has been shared.
https://twitter.com/about/resources/buttons#tweet
Widgets
Get access to data on 4,679,871 websites that are Twitter Tweet Button Customers. We know of 1,125,261 live websites using Twitter Tweet Button and an additional 3,554,610 sites that used Twitter Tweet Button historically and 576,436 websites in the United States.
Get a list of 4,679,871 websites using Twitter Tweet Button which includes location information, hosting data, contact details, 1,125,261 currently live websites and an additional 773,631 domains that redirect to sites in this list. 3,554,610 sites that used this technology previously and 576,436 websites in the United States currently using Twitter Tweet Button.