I would highly recommend caution to those thinking about this site.

You are handing over your API keys to an unknown third party.
This means that they can steal from you.

You are entrusting not just the amount you choose to "follow" another trader with, but any and all balances on that exchange.

You are NOT safe just because "allow withdrawals" is off for the API.

By trading a low volume altcoin, they can zero your account just as easily.

They could sell you GarbageCoin for an incredibly high price. They get your good altcoins, and BTC, and you get some worthless token.

Not saying they ARE doing this. But they absolutely could.
Make sure you only invest what you are prepared to lose.