Universal Windows Platform (UWP) is about making it easy for app experiences to work across devices. This is a quick guide to making UWP targeted apps work on HoloLens.
Windows 10 moves all visual design from real screen pixels to effective pixels. That means, developers design their UI following the Windows 10 Human Interface Guidelines for effective pixels, and Windows scaling ensures those effective pixels are the right size for usability across devices, resolutions, DPI, etc. See this great read on MSDN to learn more as well as this BUILD presentation.
Even with the unique ability to place apps in your world at a range of distances, TV-like viewing distances are recommended to produce the best readability and interaction with gaze/gesture. Because of that, the virtual slate has been updated (impacting all UWP apps) to:
1280x720, 150%DPI (853x480 effective pixels)
This resolution has several advantages:
The app model for HoloLens is designed to use the Shell's mixed world. This has implications on app life cycle, Tiles, and other key features of your app.
2D views are decorated with a app bar above their content. Even in full screen mode (for video playback for instance), the app bar is always visible. The app bar has two points of app-specific personalization:
Title: displays the displayname of the Tile associated with the app instance
Back Button: raises the BackRequested event when pressed. Back Button visibility is controlled by SystemNavigationManager.AppViewBackButtonVisibility.
It is important to test your app to make sure the text is readable, the buttons are targetable, and the overall app looks correct. You can test on a HoloLens, an emulator, or a touch device with resolution set to 1280x720 @150%.