BlockCypher is a cloud-optimized block chain platform powering crypto currency applications reliably and at-scale. The platform is exposed through simple web APIs and callbacks for developers to build Bitcoin and other block chain apps reliably. Built from the ground-up for scale and optimized it for high availability. Up time is 99.99%, high throughputs, linear scaling, low-latency, and no single point of failure. Web APIs, WebHooks, and WebSockets. Includes block chain explorer, creating transactions, address APIs, and others. Using these APIs, you can create a web wallet easily, monitor addresses, get notified of transactions, etc.