Honestly - I think I would buy an iPod just to be able to buy & use a Fitday app!! - if it existed - I've been wanting to do this for about ten years now - before I discovered Fitday?.... I'm not a Developer so didn't but I imagine there would be demand for this - a portable diet/nutrition app that you didn't need to be online to use.
And while this may be 'cross-post' I too am frustrated about the time-consuming logging back-in. I'd buy the FitdayPC just to deal with this - but I'm on Mac. Or is the ad revenue a better business model? I am not so worried about this, if it means that the site basic account is free to use.