A simple script to check a website for a particular string and notify if the occurances change.
Notify via pushover.net notification service, osascript and say
This was set up as a cron to check every 10 minutes.
*/10 * * * * /usr/bin/env bash /path/to/script/check.sh
This actually worked. It helped me get booked into a course that was selling out all the time.