Primecoin is a cryptocurrency based on finding prime numbers. Identifying prime numbers plays a central role in cryptography. Primecoin's unique Proof-of-Work (PoW) consensus mechanism is able to increase transaction speeds and improve energy efficiency.
The network searches for special prime number chains known as Cunningham chains and bi-twin chains, which are of interest in mathematical research.

Sphere is a smart contract platform and peer-to-peer payment network. The network has a hybrid PoW and PoS consensus mechanism and is powered by the native SPHR token, which can be swapped for an ERC20 token over the Ubiq smart contract platform.

Plus-Coin

Mobile App marketing Platform

PlusCoin has been developed to connect cryptocurrency and the real economy.
When you use access entertainment (game etc.) and F&B, you can pay with mobile commerce instead of cash.
It offers safety through blockchain technology and provides a cheaper that does not require fees.