The "Get Windows 10 app" is no longer available, but the Media Creation Tool will upgrade any PC running Windows 7 or 8.1, and you can fresh install Windows 10 on any PC using a valid Windows 7 or 8.1 key and it will activate. This is true even for versions of Windows 10 released after the "end" of the upgrade offer.

The only thing stating the upgrade offer has ended is "The Windows 10 free upgrade through the Get Windows 10 (GWX) app ended on July 29, 2016." Which is technically true, but the free upgrade is still offered through other methods.