Bing mobile app
If you don't mind me chiming in, why bother with the app at all? I only ask because maybe i'm missing something but I really like Bing and I refuse to use anything from Google Inc anyway. I set my default to Bing and just use it thru the browser. What are the advantages of the Bing app that make it necessary over just using it in the browser? I tried the app once quite a ways back and didn't see a real use, it just seemed like an extra step towards getting into my browser.
At any rate, sorry I can't be much help. If you've tried a battery pull for good measure, or have tried deleting and reinstalling the app, I wouldn't know what to say.