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 4,191,811 websites that are Twitter Tweet Button Customers. We know of 1,025,024 live websites using Twitter Tweet Button and an additional 3,166,787 sites that used Twitter Tweet Button historically and 553,119 websites in the United States.
Get a list of 4,191,811 websites using Twitter Tweet Button which includes location information, hosting data, contact details, 1,025,024 currently live websites and an additional 830,923 domains that redirect to sites in this list. 3,166,787 sites that used this technology previously and 553,119 websites in the United States currently using Twitter Tweet Button.