Google+ is an account service that allows interaction with other users through posts and pictures. This is the official link to upgrade the Google Plus SDK for iOS. Resources include download, access frameworks, upgrade, and build. Additional tools explain how to integrate Google+ into iOS, how to share to Google+ from iOS, and how to share interactive posts from the iOS app.
Some may remember yfrog as the photo sharing service previously associated with Twitter. However, since Twitter's launch of it's own internal photo sharing service last year, Yfrog has been left worse for wear. Despite the effects of this, Jack Levin (ImageShack founder) has not accepted defeat and has bravely entered the social networking arena to meet the giants face to face.