Mobile devices generate over 50% of all web traffic worldwide and up to 80% in some of the countries. Mobile-first trend is only getting started.
Mobile users spend about 90% of their time in-app and only 10% on websites. App guarantees better retention.
Mobile app revenues already exceeded 100 billion USD yearly - this includes in-app purchases and advertising. Products bought via smartphone are worth 10% of all retail revenue in the US!
Apple's IDE (Integrated Development Environment) for both Mac and iOS apps is Xcode. It's free and you can download it from from Apple's site.
Android software development is the process by which new applications are created for devices running the Android operating system. Google states that "Android apps can be written using Kotlin, Java, and C++ languages" using the Android software development kit.
Swift is a developing language used to develop applications. Xcode is the whole system, Swift is the most recent language in it.