Program that tells when a website has added a new webpage?

I know about websites/tools that tells you when a specific webpage was updated (visual mapping etc) but I can't find any that tells when a website has added a new webpage.

For example, a news article website. I want to know when they've added a new article (webpage). My issue is that not all the time a new article is shown on another webpage or category like new posts, latest posts etc. so no change to use a visual mapping software.

Anyone know of a tool or website that does this? Preferably a free one.

Hopefully this is the correct section.

Check sitemap.xml or rss feed.