[Editor's Note: This API is no longer available. The Blockr.io website now redirects to Coinbase.com. To access this API's functions, try using the Coinbase API.]
Blockr.io is a site that allows users to browse Bitcoin transaction blocks and view individual transactions and the addresses to which they occurred. The site also offers information on the addresses with the most Bitcoins, the addresses with the most transactions, and other trivia. Blockr.io provides APIs that enable users to retrieve information on coins, blocks, transactions, and addresses.