I made a bot that sent me alerts whenever La Resistencia, a Spanish TV show, had tickets available to be in the audience. It is a very popular show and tickets are usually available in their web for less than 5 minutes. I even made an app: https://play.google.com/store/apps/details?id=eu.teledhil.la... It no longer works because they added a recaptcha.

I also have a chat bot based on megahal, a bot that downloads subtitles for my torrent videos. At work I made a bot connected to slack that alerted of some server issues.