"An excellent app" - Editor's Choice from DroidAppOfTheDay.com
http://www.droidappoftheday.com/2012/11/klearkeys-transparent-keyboard.html

KlearKeys is a highly customisable keyboard that allows you to create that unique look from seemingly endless possibilities. Turn your keyboard transparent and watch your favourite applications and websites come alive. From completely transparent to completely opaque, you decide exactly how transparent your keyboard is.

Features:
● Customise background colour and transparency
● Optional auto correct with customisable colours and size
● Select from dozens of key images
● Option to float keyboard
● Split keyboard layouts
● Layout with arrow keys
● Customise key text colour / size and apply shadow effects
● Customise keyboard size with separate values for portrait and landscape modes. Take up the entire screen if you wish!
● Optional TrueShift which makes the shift key behave like ones found on hardware keyboards

Phone versions available at -
https://play.google.com/store/apps/developer?id=Touchscape+Software

Fed up with large cumbersome keyboards that take up all the room on your screen? No problem. KlearKeys lets you decide exactly how large the key text is, how large the keyboard is and where the keyboard is placed. It can even fill the entire screen if you wish!

Bored with grey keys on a grey background? No problem. KlearKeys lets you pick whatever colour you want for the keyboard background and key text. It also comes with dozens of different key images allowing you to get that look just right.

Do you miss the way the shift key works on your hardware keyboard? No problem. KlearKeys uses TrueShift technology that takes advantage of multi-touch screens by shifting keys when pressed and un-shifting them when released.

Ideal for tablets and large screen devices but works with any device running Android 3.1 and above. With numerous keyboard layouts (including split) configurable separately for portrait and landscape modes you have a highly customisable keyboard that allows you to create that unique look from seemingly endless possibilities.