Reeder (iOS) does that and it's great. When you open an item, it shows the feed content, with a prominent button that will snag the page content and run it thro

Reeder (iOS) does that and it's great. When you open an item, it shows the feed content, with a prominent button that will snag the page content and run it through a mobilizer service. I think there's an option to make that the default functionality too, though I prefer to attempt reading the RSS data first for speed. It works standalone or can sync with Feedly, Newsblur, or other services.