During the WinHEC developer conference, Microsoft engineer Don Box has stated how the company wants users to call apps on its Windows platform. According to Box, the company differentiates between Windows Apps, which will work on all Windows based devices and Windows Desktop Apps, that are only suitable for running on PCs.
The Metro interface, that was introduced during the beta stage of Windows 8, was renamed after a conflict with German retail giant Metro AG. Microsoft renamed the interface and its apps to Modern, however many continued to call the interface Metro or TIKAM (The Interface Formerly Known As Metro).
Another frequently used name for the Metro/Modern apps was "Windows Store Apps", which helped to distinguish between the Modern interface apps and classic desktop application in Windows 8.x. However after Microsoft made it possible to also run Modern apps in the classic desktop environment, that name didn't really cover it anymore.
With Windows 10, Microsoft introduced apps that work on all Windows based devices. These apps were previously denoted as Universal Apps, after the universal nature of the platform. However with the statement of Microsoft's Don Box, it's clear they should be called Windows Apps.
