HelloBlock

HelloBlock provides node hosting for both MainNet and TestNet, and gives HTTPS access to Blockchain Data through a RESTful JSON API.

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Bitcoin Charts API

Bitcoincharts provides a simple API to most of its data. You can use this API to include markets data in your websites, mobile apps or desktop applets.

Block inspector / API

Documentation for the Block inspector blockchain and transaction API.

Blockchain Demo

Blockchain Demo is a visual explanation of the blockchain.