I don't have iPhone, but on my Android tablet I can open exported reports with Opera browser. Since tablet screen is small, all other tabs after "Race Results" collapse into it, so I need to press on "Race Results" tab header and drop-down with other tabs appears, they are selectable.
I also have Chrome on tablet, but for some reason only Opera available for selection when I click to open html file, so I was not able to test Chrome.
Make sure that your browsers on a phone allow JavaScript to work. Tabs and some other stuff will not work without it.