Congrats for the awesome journey! A lot of useful insights that we will use for our startup too, answering on Stack Overflow is a thing that I didn't think about till now. At this moment we are using uptimerobot for our creative-tim.com and for our demos, blog etc. We will give a try to Cronitor too. The link for "
http://startupli.st/" didn't work, do you have another one?