VisualPing

It is an app that takes screenshots of any website and sends them to your inbox. You can schedule them hourly, daily, weekly or whenever you want. The best part is that you'll be the first to know if your favorite web page posts a new update or if your personal website takes a turn for the worst.

Obvious.io is a visual monitoring service for websites. Obvious.io uses computer vision to 'see' your website in the same way your customers do.

Awareness is essential to success, but being aware at scale is hard. Especially in an age of rich infographics and process generated media. Leverage the diff.io API to make awareness at scale easy. Track any page, at any frequency.