Right now we don't have any demo, but you can sign up and if you like it you can choose to upgrade. Upgrade gives you more monitors and more intervals but everything else is the same between free and non-free accounts.
I'd like to see it as well (screenshots would be fine, a demo better, of course) but I'm not going to bother taking the time and trouble to sign up just to be able to see if I might like it.
I realize I'm only a single person but I would think many others are the same way so it would seem that you're unnecessarily putting up roadblocks to acquiring customers.
