As was spotted in a build last week, Microsoft has formally announced the Windows App Preview Program, allowing Insiders to sign up for previews of individual Windows 10 applications.
Build 17101 RSS
Microsoft released a new Windows 10 for PCs Insider Preview build today, bringing the build number to 17101. Along with new features, it contains a long list of fixes, improvements, and known issues.
Microsoft today released two Windows 10 for PCs builds, including 17101 for the Fast ring, and 17601 for those that chose the Skip Ahead option, making it the first build from the Redstone 5 branch.