Recently, Microsoft has just released a new Bluetooth keyboard for smartphone or tablet, the Mobile Keyboard 5000. By looking into the rich features of these two terminals, releasing a keyboard which is compatible for all of the operating system is very reasonable to call a good business.
Mobile Keyboard 5000 supports iOS, Android, Windows Phone and Windows. Of course a few are missed in the list but it is enough to cover the majority market. The keyboard is very elegant and the price is $49.95.
You can download Mobile Keyboard 5000 manual here (PDF format).
In case you want to use with Mac OS for Mobile Keyboard 5000, you can download the drivers from this link.