Google chrome missing and I can't reinstall it

I have had google chrome installed on my iPhone 4S from the start (also installed on my iPad) but since the upgrade to ios6, my iPhone no longer shows the google chrome app although it still appears and can be used on my iPad.

When I visit the App Store the google chrome app comes up to view in search but the "free" button is greyed out and I can't click on it. I have settings in my iPhone for chrome (like in the notifications) but its like it is no longer on my phone and I can't re-download it.

Am I doing something wrong, or does anyone have any suggestions?