One of the many announcements at Microsoft's Windows Developer Day was "Project Rome," a way for Universal Windows Platform applications (apps from the Windows Store) to have cross-device services. In addition to supporting all the various Windows 10 platforms (PC, Windows Mobile, Xbox, etc), Microsoft has also released the Project Rome SDK for Android.
Project Rome for Android is a bit limited at the moment, as it only supports Android to Windows communication (and not the other way around). The SDK enables Android applications to authenticate with a Microsoft account, then scan for Windows 10 devices on your local network.
Once a remote device is connected, developers can use the Remote Launch API to trigger opening a specific application or website (demo here). In an SDK update "coming soon," controlling remote Windows apps (like a media player) from Android will be possible.
As Windows 10 gains more and more market share, and developers start switching to Universal Windows Platform apps, we'll start to see this sort of integration more and more.
- Windows Blog