Unlike Killer Instinct, Gears of War 4 and Forza Horizon 3, Halo Wars 2 won't support cross-play multiplayer accross Windows 10 and the Xbox One.
Microsoft makes some nice cross-platform apps for iOS and Android via its Microsoft Garage team of hackers. Some of those apps are better than the ones Apple and Google ship themselves, such as the Arrow Launcher for Android. Another good ... Read more
At Ignite 2016, Microsoft provided confirmation that Windows 10 authentication will be coming to iOS and Android devices.