Java programming language is one of the most preferred language when it comes to Android app development. An object-oriented programming language developed at Sun Microsystems (now owned by Oracle), can be run in 2 different ways either in a browser window or in a virtual machine that can do without a browser.
The primary programming language for iOS apps, Objective-C was chosen by Apple to build apps that are robust and scalable. Being a C-language superset, it does have a number of functions that precisely deal with graphics, I/O, and display functions. Moreover, as part of the Apple development framework, Objective-C is fully integrated into all iOS and MacOS frameworks. However, it's now slowing being replaced in the Apple ecosystem by a more powerful language called Swift.
Swift is the latest programming language to foray into the Apple ecosystem, mainly considering its prevalence in writing code for Apple's latest APIs, Cocoa and Cocoa Touch. Even though it is a language written to work along with Objective-C, the Cupertino company is making it but obvious for iOS developers to turn to Swift for complete programming.
The challenge with native platforms is a doubling of cost/effort when you want to cover more platforms.
HTML5 is the ideal programming language if you are looking to build a Web-fronted app for mobile devices. Although it makes various data types simple to insert, account for different screen sizes, rationalize input parameters and even level the browser playing field; the problem with HTML5 is that it is still a proposed standard.
This is the most appropriate and robust programming language when it comes to building mobile apps for Android and Windows - and mainly for low-level programming it's still the go-to language on platforms for mobile app developers. As a powerful programming language, C++ allows mobile apps to be developed for practically every purpose on every platform that exists.
The most coveted programming language for Windows Phone app development, C# does the trick for Microsoft that Objective-C does for Apple. Although, Windows Phone platform couldn't emerge as the game changer in the mobile application development industry, for loyal Microsoft users, C# makes the perfect programming language to build the robust Windows Phone apps.