Nearly three times as many tablet owners and twice as many smartphone users access news primarily through browsers rather than apps. -- I think this is because the apps leave something to be desired with regard to functionality.
Facebook Reveals Mobile News Feed Ads and Massive Logout Page Ads
Facebook recently began allowing advertisers to choose where they wanted their ads shown on Facebook. Their options are across all of Facebook, desktop (feed and sidebar), desktop news feed only, mobile and desktop news feeds, or mobile news feed only.
All-Star Cast Invests 750K In Ben Huh And Matt Galligan’s Mobile News Startup Circa