#HashTag is a web application that demonstrates the working of a hashtag system found in social networking applications like Twitter, Facebook, Google+ and so on. This demo uses a PHP - MySQL based server to generate the dynamics of the application. A hashtag is a word or an unspaced phrase prefixed with the number sign ("#"). It is a form of metadata tag. Words in messages on microblogging and social networking services such as Twitter, Facebook, Google+ or Instagram may be tagged by putting "#" before them, either as they appear in a sentence, (e.g., "New artists announced for #SXSW2014MusicFestival")or appended to it. Hashtags make it possible to group such messages, since one can search for the hashtag and get the set of messages that contain it. A hashtag is only connected to a specific medium and can therefore not be linked and connected to pictures or messages from different platforms. Users can post their comments with hashtags which will be detected by the app and will be marked as Hashtags within the app. Users can search the app with hashtags which will result out posts with corresponding hashtags. Happy Hashtagging !