Groestlcoin is a blockchain payment protocol with a number of technical innovations and an active developer community. Groestlcoin was the first coin that activated SegWit and supports the Lightning Network. Transaction fees are very low and it claims to have instant payments. It is also one of the only coins that can be sent over SMS.
Groestlcoin's active developer community has made the payment protocol very adaptable, and it a popular coin among many crypto investors. Groestlcoin has an ASIC resistant Proof-of-Work consensus mechanism.

Apollo is developing an all-in-one cryptocurrency platform, based on the APL coin. Apollo was created as a fork of NXT, and has a very ambitious plan to integrate a variety of services under one platform, with a strong focus on privacy. Apollo's blockchain is called Hermes and has a Proof-of-Stake consensus mechanism. Some of the features that Apollo's marketing materials claim they are working on are: private transactions with IP masking, smart contracts, encrypted messaging, file sharing, a decentralized marketplace, voting system for governance, decentralized data storage, and a wallet with a built in exchange. John McAfee, a notable blockchain enthusiast and antivirus pioneer, joined the project in October 2018.

Qtum has been described as a hybrid between Ethereum and Bitcoin. Qtum is a smart contracts platform that places a strong focus on value transfers as well as decentralized apps. Qtum enables users to create smart contracts on the platform and conduct cryptocurrency transactions.
Qtum has a Proof-of-Stake (PoS) consensus algorithm. Several decentralized apps are already using the platform.