BitDouble is blockchain based Cryptocurrency using hybrid scrypt of Proof-of-Work (PoW) and Proof-of-stake (PoS) algorithm. Users can get BitDouble through mining, staking and buying with Bitcoin and Altcoins during the ICO. During a new data transaction in the blockchain, it retargets every block in the chain. It can be used like the government legal tendered currency but it is available only in digital world. The concept of BitDouble may look similar to the first Cryptocurrency of the world, Bitcoin. But is has many advantages.