It would appear that Apple have changed the way homescreen/standalone web apps work in iOS 6. According to various blog posts (example) these apps now get their own dedicated s
I can't verify the cache being cleared properly but this worked for me :
In order to do this, you need to allow Web Inspector on your iOS device. Go to Settings > Safari > Advanced > Web Inspector (it has to be active) And you have to activate the developer menu on your computer's Safari. Go to Preferences > Advanced > Activate Developer menu
Somehow the Webapp cache got cleared and i got the non-cached code.