Sign in UI appears in browser but not in app

Hi -
I am just getting started and have done the basic tutorial. I modified the Simple Todo to make profiles instead. Not a lot going on. Deployed at looks as expected with “Sign In” appearing after a brief pause. Then I go to Run on mobile device with the URL above and the App loads with text but no Sign In. I am on iOS/OS X. Sign In appears on device when browsing through Mobile Safari. Does not appear in Simulator. Xcode gives a few warnings (Semantic Issues, Value Conversion Issues) but no Errors.
Any ideas?