Crafting an app for a single device is very hard enough, but nowadays the developers have plenty of form factors to tackle the problems. Microsoft announces Universal Windows apps for the PCs, phones, and tablets and it offer you to create apps for all sort of Windows platform. People used to write theoretically about an app in Visual Studio once but now, the universal app will take on a different appearance based on the device it is running on to work with.
Windows Universal application will allow developers to create apps that work on both tablets and PCs as well as on smart phones and it also allow sharing the large parts of the code. It also allows downloading it for all compatible Windows devices. Even for the Xbox One, Microsoft will consider the developers participation. Microsoft explains the developers that they can now link Windows Store and Windows Phone apps to create a universal Windows app to provide a customer experience, and the company hopes will increase both paid and free app downloads across device types.
Microsoft announced the consolidation of the application pricing to match the Windows Store and the Windows Phone applications. Microsoft insists that you need to buy separate apps for separate versions of the operating system essentially, because, Windows is now all one big operating system now. Microsoft aims to make the process of buying an app easier.
The apps must be purchased only once as there is a onetime customer for purchasing the app. People, who buy a Universal App, can use it on all devices.
If you buy an app for your Windows 8.1 laptop, you can automatically download it to your Windows Phone. But, Apple and Google does not do this. If you buy an app on Mac OS X for your iMac or MacBook, you will still need to download and if you buy an app for extension, you will still need to buy another app for Android.