My RSS Feed Reader app was one of the first apps to be approved in the Office Store. It displays any Atom or RSS feed in an app part that blends nicely into the site theme. It is in use on more than 1000 sites. It’s free and open source, so if you have an Office 365 tenant please go ahead and check it out.
Currently I’m working on implementing an AutoCAD drawing preview app for SharePoint 2013 and Online. Please let me know if your company is interrested.