How to check if your Moodle site goes down

Unless you are sat in front of your Moodle installation 24 hours a day, how will you know if the site goes down?  Wouldn’t it be nice to receive an email or a text if Moodle stops responding?  I happened to stumble upon the website below:

Are My Sites Up?

The service will check your website several times throughout the day and alert you (via email or text) if anything goes wrong.  It’s a great piece of mind to have, especially during exams and when you are away from the office.