I found this neat video on how to create an Ethereum Blockchain Voting Application with JavaScript and Solidity! Take a look!
Created by Siraj Raval
https://www.youtube.com/channel/UCWN3xxRkmTPmbKwht9FuE5A
Oh, by the way, are you looking for a decentralized exchange?
Try BitShares!
Made by the creator of Steemit!