I'm one of the developers of TryAgain, an add-on for Firefox that keeps trying to load a webpage when the server cannot be reached.
A user recently suggested having the add-on check if the website you're trying to reach is down, or just blocked for the local machine. I was therefore hopeful that there might be a website similar to downforeveryoneorjustme.com that has some kind of API that could be used to poll a domain to see if it is accessible to the greater public.
I've tried contacting downforeveryoneorjustme.com and Uptime Auditor, but neither have responded. Does anybody have other ideas?
If you only need simple functionality to verify whether the site is visible to the some service (ex. http://downforeveryoneorjustme.com), I think the API is not necessary, you can simply get:
http://downforeveryoneorjustme.com/aaa.google.com
And check if in response you can find:
<title>It's not just you!</title>
or:
<title>It's just you.</title>
For example in unix-like environments you can do something like this:
wget -q -O - http://downforeveryoneorjustme.com/aaa.google.com |grep "It's not just you"
And check exit code. Maybe you should do something similar in your code?