that site is a scam, there was one alike called coin-doubler, and one before that called coinx2(which scammed me too, 1 btc...), i believe they are the same people
there is no easy way, unless you want to scam someone...
better to join signature campaign as they pay well right now, just rise ytour activity first
Those are indeed scams, but the site OP posted seems like its paying. As long as you aren't the last guy.. it may work.
Maybe is more risky with bigger amounts, but what if you try with 0.1?
If someone tries let us know, im not going to risk it personally.