The Xbox app on Windows has been going through major transformations for some time now as Microsoft expands the software to work better on handheld gaming systems. Last year, the app became a universal launcher for third party games and even other storefronts. Now, there is another upgrade being tested, and it a feature that Steam users have had for many years: adding third party games and apps into the launcher. Spotted by PureXbox , the preview version of the Xbox app now sports a plus...
