FREE Coin is an Ethereum-based token with a focus on being inclusive and encouraging cryptocurrency adoption. Their goal is for the token's price to increase in value, until its price is close to the USD. FREE Coin's site does not provide any details about their development plan or what specific advantages their network will provide.

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.

Soarcoin is an Ethereum-based token that was created by a company in Singapore called Soar Labs. Soarcoin's total supply has already been released. Since it can not be mined, the price of the SOAR token will be completely dependent on supply and demand. The company's marketing materials place an emphasis on low transaction fees, privacy, and fraud protection, but it does not appear to offer any noticeable benefits to other cryptocurrencies. Soar Labs also has plans to create a cryptocurrency exchange called Soar Ex, that will focus on the Southeast Asian market.