If you're looking to get a peek at what cool features are coming to Windows apps in the future, then you pretty much need to run an Insider build. But Microsoft realizes that some folks don't want to run beta software on their machine, which is why it's developing a way to test apps inside retail versions of the OS. Right now, a handful of Windows 10 apps have been opened up to let users see what's coming down the pipeline, regardless of their Insider status.
The program was picked up by Thurrott.com, and currently enables would-be testers to preview Windows Camera, Microsoft Photos, Alarm, and a handful of other apps. Microsoft isn't saying too much about how this will work in future, although Microsoft's Brandon LeBlanc did confirm the program's existence. In a tweet, LeBlanc wrote "This is us just trying to make it easier for those who want to test app updates on both Insider builds or retail." Hopefully, in the not-too-distant future, we can all put our two cents in and make these apps the best they can be.