Instagram is a mobile, desktop, and Internet-based photo-sharing application and service that allows users to share pictures and videos either publicly or privately. It was created by Kevin Systrom and Mike Krieger, and launched in October 2010 as a free mobile app exclusively for the iOS operating system. A version for Android devices was released two years later, in April 2012, followed by a feature-limited website interface in November 2012, and apps for Windows 10 Mobile and Windows 10 in April 2016 and October 2016 respectively.
Instagram lets registered users upload photos or videos to the service. Users can apply various digital filters to their images, and add locations through geotags. They can add hashtags to their posts, linking the photos up to other content on Instagram featuring the same subject or overall topic. Users can connect their Instagram account to other social media profiles, enabling them to share photos to those profiles as well. Originally, a distinctive feature of Instagram was its confining of photos to a square; this was changed in August 2015, when an update started allowing users to upload media at full size. In June 2012, an “Explore” tab was introduced, showing users a variety of media, including popular photos and photos taken at nearby locations, trending tags and places, channels for recommended videos, and curated content. Support for videos was originally launched in June 2013, and had a 15-second maximum duration and limited quality, with Instagram later adding support for widescreen and longer videos.