Omnimo UI is described as 'Do you want your desktop to look futuristic, informative and stylish? With Omnimo you can create amazing homescreen-like desktops that will fit your every need. Inspired by the Metro UI, it delivers highly functional interactive panels to the desktop and more!'. There are three alternatives to Omnimo UI for Windows. The best alternative is Immersive Explorer, which is free. Other great apps like Omnimo UI are WinMetro (Free) and Windows 8 Transformation Pack (Free).
Immersive Explorer is an open source alternative to the default file explorer included in Windows (known as Windows Explorer). Although it is not a Windows 8 "Metro application", Immersive Explorer is designed around the "Metro" user interface guidelines.
WinMetro is specially designed to bring the newly introduced Windows 8 Metro UI to Windows 7, Windows Vista and Windows XP. It offers an easy solution for old version Windows users to try and enjoy the tile based Metro UI.
Windows 8 Transformation Pack turns Windows 7/Vista/XP user interface to Windows 8. Including Windows 8 Boot Screen, Login Screen, Themes, Wallpapers, Icons, Sounds, Fonts, Metro/Modern UI, Aero’s Auto-Colorization, Taskbar UserTile and more.