startisback.com
StartIsBack is a shell enhancement that returns a start menu and start button to Windows 8 and Windows 10, behaving as in Windows 7. It also offers taskbar skinning, jump list replacement, centered taskbar icons and Start menu customization. Versions exist for Windows 8, 8.1 and 10, with StartAllBack for Windows 11. A trial is available and a license key costs $4.99.