Are there any plans for listing SGL on exchange ?
Yes, the Devs are actively working on it and have spoken with several exchanges. I think it's important to realize that just like Ty said they will be covering the fee for listing the coin on exchanges. Binance charges 75 bitcoins to list on their exchange currently. That's $1,021,501.12 to list with them... That's obscene. Some others are more reasonable, but still costly. The devs are paying that out of their own pockets. Remember SGL isn't worth anything until it's listed. They need this to succeed or it's a massive waste of resources for the entire team that is backing it and developing it.
If you haven't already check out the Slack and Subreddit.