RigPool is a Bitcoin mining pool that pays miners through a PPLNS payment system. The pool has a 0% fee and the minimum payout is made when the user reaches 0.001 BTC.
Although NiceHash is usually regarded as a mining service, it's better to say that it's a kind of a platform for selling/buying cloud mining contracts. What is special about NiceHash is that users can opt for both selling and buying the hash power on this platform.
Sapphire is a Graphics card producer that can be used in mining alternative crypto currencies such as Ethereum and Litecoin. SAPPHIRE Technology is a leading manufacturer and global supplier of innovative components and solutions for PC systems for both consumer and professional applications. From its origins in the design and manufacture of state-of-the-art graphics add-in boards, the extensive SAPPHIRE product range has grown to include a broad range of professional and embedded products. Founded in 2001, SAPPHIRE is a privately held global company headquartered in Hong Kong.