Thank you for visiting Snitch.io. Unfortunately, your statements are still not correct.
I signed up for a free account on VA and put in a site with a revoked SSL certificate. It has not generated an alert. It has been over 12 hours. It is still prompting me to insert the JS on my site, by the way.
As to your second point. Snitch isn't simple alerting.
It runs a full range of tests on an SSL certificate: checking for expiration, checking for revocation, checking that all of the intermediate certificates have not been revoked, checking the certificate is valid for the domain (including SNI), checking that the certificate isn't signed with a weak algorithm such as SHA-1 that Chrome is about deprecate, checking that the certificate has not been changed (incorrect server config, malicious intent...)
Snitch is not targeted at people who just need to know if their site is up or down.
If you are are a business and users browsing to your site get a big red warning in their browser because your SSL certificate is expired/revoked/weak/misconfigured - that is a problem and you lose money. That is what Snitch is addressing.
http://voodooalerts.com/free