DailyTracker is really good and useful, but it's not without problems. The first is that the menus are fairly complicated and the help page gives very little actual help.
Second, it doesn't explain the difference between things like "Value" and "Value+", which can be confusing to newbies.
Third, there's no way to sync across devices. I know the developers tout the fact that you don't have to sign in to anything, but signing in is what allows other apps to sync across devices (or at the very least, have it sync with GameCenter to do the same thing). I hate that if I put the info into my iPad all day, then go out with my iPhone, I have to either re-enter all the info or just go without knowing.
And finally, and this is just nit-picking (but would be nice), there is no option to scan a barcode to enter all the relevant nutritional data like other apps allow you to do.
In all, I'd give DailyTracker 3 1/2 stars, but I rounded up to be nice to the developers, who I'm sure are hard at work and will hopefully address some of these issues.