A war among Twitter, Yahoo and Facebook for sharing photos on mobile units is heating up.  Twitter and Yahoo’s Flickr recently announced that they are implementing new tools to adjust color, size and style when uploading photos to mobile devices.  This is creating a direct challenge to Facebook’s Instagram.  Few weeks before the announcement, Instagram made it hard for users to upload photos in tweets.  Twitter and Yahoo’s Flickr used software developer Aviary to develop the photo tools.  Twitter now allows users to add audio and video to their tweets and Yahoo upgraded its e-mail allowing faster and easier navigation for mobile units.

Launched in October 2010, Instagram claims that 80 million customers use its product to share photos on iPhone, iPad, and iPod Touch.  It has a distinctive square shape to its photos oppose to 4:3 aspect ratio typical for mobile devices.  Facebook completed acquisition of Instagram in August 2012 when the Federal Trade Commission approved the deal.

Developed in 2004, Yahoo acquired Flickr in 2005.  According to Yahoo, Flickr has 51 million users and attracted 80 million visitors in 2011.  Flickr has an app for iOS and can run on any Android device and Windows Phone 7 operating system.