I'm not affiliated with these guys: http://pushmon.com/ http://pushmon.com/ It's not self-hosted. Other than that, you create some type of a link on their websi

I'm not affiliated with these guys: http://pushmon.com/ http://pushmon.com/ It's not self-hosted. Other than that, you create some type of a link on their website, and you have to go there every once in a while. You also set up notifications (SMS, email, etc), and if you don't go to their link for some amount of time, they send out alerts. It's marketed for checking if script ran (script would go to website after it finishes, and lack of that ping results in alarms).