Sleeping Spider is a Feed Reader
Add the links that you want to track and visit later to find out what has changed to them. It also parses RSS, so it can be used as an none intruding feed read.
2017 Dec 30 - added more space to the server
Drag this bookmarklet to the Bookmarks bar of your browser. Add to SleepingSpider...
The price is $50 a year. 30 days free trial.