I read things like "multiply your bitcoin" and "free bitcoin". Sounds very dodgy, I stayed away. I'm surprised they can convince people to get involved.
There are many types of scams present in the online market so remember one golden rule while investing. If you see any program is offering your profit percentage for investing your bitcoin with them, simply stay away, because they are called ponzi. They will give you interest for first few days, and then they will just disappear. Ponzi is the most common type of scams in online industry.
Also if any program tells you to double your bitcoin in few days, avoid them more because here you win't receive a single dime back. They will run away with your entire invested amount.