It's literally a site that is hosted on a free domain name, with a pretty generic template that they probably grabbed somewhere for free. No effort or monetary investment in a domain name has been even made by these scammers to make this seem realistic.
They just flat out claim that it's a bitcoin doubler, which is pretty much synonymous of a scam right now.
If they really had this method of doubling bitcoins, why not keep it secret and use it themselves, instead of offering you this 'great' investment opportunity?
If that's still not enough proof to you, then just look at their recent payouts. You can see that these TXIDs don't even match the time at which they claim they were sent.