You may have noticed in Apple's recent iTunes update that they played a little game of "hide the app update button." Well, not to spoil the surprise, but we uncovered it.
Instead of its usual location across the bottom of the App pane in iTunes, you now have to select the new Updates tab located above the pane. Once selected, an Update All Apps button will appear in the previous location on the bottom.
Apple also decided to festoon any app in need of an update with a red Update ribbon. Logically, you might think that you could click the ribbon to update these apps individually -- but no. Instead, you have to be in that previously mentioned Update tab (which is devoid of red ribbons, oddly), and from there you can click each app to update them individually.
It's honestly less confusing than it sounds. Just watchabove and all will be made clear.