The Matic Network is a sidechain based scaling solution for public blockchains. Matic aims to allow developers to better scale their Ethereum DApps by using a version of Plasma, along with side chains that use a PoS consensus mechanism. Matic plans on supporting other blockchains as well in order to facilitate interoperability.

Ignis is a blockchain platform that is being developed by Jeluirda; the company behind Ardor and Nxt. Ignis is a child chain of the Nxt blockchain. Jelurida is developing blockchain platforms that will enable users to develop decentralized applications, and will be based on a parent and child chain architecture.
Ignis allows users to create child chains with specific features and to create tokens that meet their needs. This project is closely related to Ardor and Nxt.

APIS is developing a masternode mediation platform that will lower the barriers of entry for users wanting invest their coins on their own masternode of a network. A masternode is a type of node that has additional voting influence and block rewards, on a Proof-of-Stake network. Investors are able to place coins on a masternode and receive a stable interest from the block rewards; similar to interest that is given in a bank. APIS will allow users to invest in masternodes without having to deal with the technical requirements or stake a prohibitively large number of coins.
Their network is powered by the Ethereum-based APIS token.