Ever since mobile phones have become more powerful in terms of their battery capacity, their processing power and the OSes that they run on them, mobiles have been running more and more versatile apps. This has been fuelled by the open source community of Android developers, helped partly by the iOS development community as well. As of October 2018, there are 2.1 million apps in the Google Play Store and around 2 million apps in the App Store. This is an unprecedented number of apps, and this number is only set to grow in the next few years.