Even if this app IS something interesting, nothing makes me want to sign up.

Here's why:

I think your landing page copy needs some work. Immediately when I see create your own private network, I am thinking VPN. "Socialise in groups," to me seems ambiguous, isn't socializing an inherent group activity.

In terms of design, there is low visual affordance. I am not enticed to roll over those icons, or click on the sign up button. I think "Create your own network now" is a good call to action, should be more prominant and should be followed up with a start now link or something, or get started, something to encourage the user a bit. "Sample network" shouldn't be directly next to "Create Network", it confuses what action should be taken. Sample network shouldn't be a button, just a plain link. Also that blue is far from harmonious with the rest of the color scheme you have working. The text below the icons needs more contrast with the background.

I want to see a screenshot / screencast to show me what I am getting. I still can't imagine what this thing even is.