In case anyone ever comes across this, it can be done and works really well. After setting up you can download the 'app' from Chrome, Firefox or Safari. When you do not have any internet connection the tour will still work, and what is neat is that it will update the next time it connects online. Once the user has downloaded the tour to their device it acts and looks like an app.
There are some limitations to the offline storage for different devices, but for the majority of tours will work fine.
If there is interest I can put together a step-by-step guide.
