http://www.pulseway.com/
Another online free monitoring tool, looks a tad more advanced than uptimerobot.
Have you given it a try yet?
Not yet, but I have found uptimerobot really handy so when I read about this one on reddit I figured I should pass it on.
Probably going to take a closer look later on.
Installed it on my home domain and hyperv host. Actually very very very slick system they have.