Google Maps web app not working??

I have not (for obvious reasons) bothered much with web apps since the original iPhone but given the current (and in my view, somewhat overblown) furore over Apple Maps, I thought I would put try out the Google Maps web app on my recently purchase iPhone 5. Weirdly, however, it doesn't work. The app itself loads but I am presented with a blank page and nothing happens when I click the target icon. This happens in both 3G and wifi. Location Services is on (and I am using O2 in the UK). Anyone got any ideas? I'm scratching my head over this.... Thanks in anticipation