In 2010 the word “app” listed in the world dictionary so now we elaborate in simple word what is app and why all over world celebrate the this day so first of all what is app actually app word derived from the word Application and short form of Application. Now a day million of app registered in Google app store iOS etc. Day by day new innovation of technology faster and we use latest mobile but all over world now use apps. Facebook or Google is a biggest site of the world and all over world now connect these websites but when mobile technology not innovative than these site use on computers and laptops when mobile technology fast than users convert to mobile and use all sites through mobile. Must Read: Watch latest English & Indian movies Google launch play store for the mobile applications millions of app on Google app store so why need app in our life so now we describe it when we use this sites on mobile than we have not platform than only one platform for us this name is Internet explorer all over word can find anything than used only one platform this name is Internet Explorer so Google world 1st search engine launch her app Google Chrome and all user install app mobile phones and access Google easily. After that biggest people site use the app and develop personal app to connect users easily like Facebook, YouTube, Instagram & Twitter develop her personal application because it is very easy to user who connect this site just open app and login the site without use other platform direct access the site. But now a day millions of apps registered on Playstore and iOS.