Instagram is an online mobile photo-sharing, video-sharing and social networking service that enables its users to take pictures and videos, and share them on a variety of social networking platforms, such as Facebook, Twitter, Tumblr and Flickr. A distinctive feature is that it confines photos to a square shape, similar to Kodak Instamatic and Polaroid images, in contrast to the 4:3 aspect ratio typically used by mobile device cameras. Users can also apply digital filters to their images. The maximum duration for Instagram videos is 15 seconds. Support for the app is available for iPhone, iPad, iPod Touch, and Android handsets, while third-party Instagram apps are available for Blackberry 10 and Nokia-Symbian Devices.