Till 2016 The number of App Downloads was at 50 million and After that it increased to 150 millions & and in 2017 it went to 197 million , There experts say that around 350 millions apps will be downloaded by 2021. That is the beauty of mobile application and the market of mobile application. http://usauk-classifieds.com/category/265/Computer/listings/17169/Android-App-Development-Company-Chicago.html