TL;DR I made a free uptime monitoring website, you can monitor any number of websites and they get checked at 5 minute intervals
I really like uptime robot. I think it’s great. Uptime monitoring as a service is super simple conceptually. Make a get request at some interval, send an email or a text message or notification or something when a site goes down. There’s all sorts of ways you can take it too. You can add status pages, other types of monitoring, ip addresses, cron jobs, multiple types of notifications, heck you can even make a mobile app so you can see your monitors on your phone and get push notifications when they’re down. You can even do all of those things combined to make a great uptime monitoring service.
So for me I think just free website uptime monitoring from one server is a good start, I think I have one person besides me using it, so I’m not in a hurry to add more features. If I get quite a few more free users, then I’d probably start the feature train with status pages and move down to multiple types of monitors.
There are way better ones of course, even free ones that are better, but I figured I’d throw my hat in the ring.
Here’s a list of other uptime monitoring services just off the top of my head: