We mentioned this to a couple of friends who said they needed the same simple monitoring. Having people tell you they need something is a great motivator, so we built cronitor in a couple of weekends and are putting it out there. We'd love feedback and suggestions on how to make it better. Thanks!
1. crash - any runtime error that causes your script to stop execution abruptly.
2. un-handled, non-crashing error - db connection failure, remote api failure, file not found, etc. The script may continue execution, the results may not be logically correct.
3. concurrent execution - What if an instance of cron is not over by the time the next instance should start? crontab will simply start the next instance.
4. internet connection error - even the notification mechanism will fail if it depends on an active internet connection.
Your service is a very valuable one, and a challenging one too I believe. You can do a lot many things in cron monitoring and reporting.
There are some disadvantages to self hosting a monitoring tool. But certainly there are circumstances where self hosting is very important.
I could certainly see us releasing code for the website and monitor daemon under an OSS license at some point.
Thanks for giving it a look!
We built an end to end proof of concept our first weekend on it, then spent another Sunday polishing it as well as a few hours here and there a couple of evenings.
I would suggest not to lower the prices :-)
EDIT: I prefer to pay more than $20/mo if this means that your product won't end up being stale and unmaintained.