Apps are a Plus in Hangouts Wednesday, June 27, 2012 | 1:06 PM over 200 apps built for hangouts  the average duration of a hangout increase by 2.5 times when participants use an app  1 in every 3 hangouts use an app.  Today, we are introducing a new set of featured apps built by developers around the world that provide fun and entertaining activities for our users.  Google Art Project : Explore collections from around the world with thousands of artworks photographed in extremely high resolution. You can play an art guide and take your friends on a tour of different museums.  New YouTube App : Create, control, save and even share playlists of videos with friends—all inside a hangout.…