http://www.wpcentral.com/nextgen-reader-receives-windows-81-upd
Here are the changes included in the latest release for Windows 8.1:
•Added large size live tiles.
•Support for portrait mode and 7-8" screen devices.
•Support for resisable snap views (or docked mode).
•Snap app and open articles directly in side by side view.
•Tap right edge or click three dots on mouse hover in articles list
for quick actions.
•Tap or click feed title in the grids view to open item directly in
browser.
•Share to Facebook and Twitter directly from app (Buffer support
coming soon).
•Quick access to mobilisers and better confirmation prompts for "mark
all read", etc.
•Lots of other improvements and bug fixes.