The odds calculator is already a feature in the new Windows Phone app, though it still needs some work. I'll be making my code public sometime soon so that other people can see how I did it and it can be integrated into the other apps.
Many of the features that modify how the actual game is played would require an official app as I can't get that information, at least, not easily. I could theoretically scrape the currently loaded webpage to add some of that, but that is more hacking than anything else.
I am still looking into BOB and exploring the possibility of getting Grease Monkey to work in a mobile browser. If I can do this I could simply use BOB instead of reimplementing most of the features.
Out of curiosity, how much would you be willing to pay to make the app premium? That is, removing ads.