DeltaDex

Unique features:

True Dex
The exchange is fully decentralized, it is completely controlled by a smart contract deployed on the EOS platform. Everything is on-chain (e.g. transactions, order books).
There are many advantages of a true DEX, including transparency, security and reliability.
Immutable smart contract.
The exchange has adopted the Temporary Immutability pattern (proposed by JonathanLEI).
This means that no one will be able to modify the exchange logic or control users' funds manually during the immutable period (even the contract owner will not have the power to modify or control anything).