Well. I just purchased and downloaded (within the past hour or so) the latest version of the app so I assume its the latest possible version available; I clicked on it and paid for it right from the Stardock homepage.
As for Windows; I happen to wish to use Groupy in my workplace. As with most companies or agencies, the Windows version is controlled by the IT Department. It's not the employee's choice which Windows version he might prefer. This is the norm.
Additionally: Microsoft Windows10 has a whole new world of Windows versions depending on the maintenance plan one's company cho.ses. It's not just a matter of 'what is the latest'; Windows10 versions have different 'tracks' or 'paths' one's company is on.
I'm extremely pleased with Stardock's product called 'Fences'. Great productivity tool. I use it daily.
But if 'Groupy' is not yet written in a way so as to meet basic compatibility standards for the new way Microsoft releases operating systems, perhaps Groupy needs serious re-programming.
Update on what I see on my PC: I notice now that 'Groupy' is present in the taskbar for Win10, Windows File Explorer. Gee, so...I can group as many instances of Windows File Explorer together, as I might wish. That's nice but hardly what I expected. I hope its related to the bug we're discussing above, wherein Groupy is not yet compatible with every version.
Anyway. To my way of thinking, after installing 'Groupy', it should be visible in every application window no matter what type of app. If the only purpose it has is to group my open Windows File Explorer windows together as one Windows File Explorer window, that is a nearly useless benefit.
Philosophically speaking: as computing environments around us get increasingly complicated (and they certainly are) every new product should be compatible with every platform. Otherwise don't create it or offer it for sale; as it will bound to be out-of-date in one way or another.
This isn't utopian; I can name dozens of products I've been using since Window 2000 which still work in Windows10. It can be done, if software companies start thinking this way.