IMO, this tab seems rather redundant, as you don't really do anything in that tab and you can also access the page (which is a pop-up, rather than an actual separate page) from the Booster icons in your Hero (first) tab.
When you start your game, you always start from that first tab, so it should be an easy enough thing to do to show an exclamation (!) mark next to any Boosters that require buying/extending (actually, I think this is done already?). In addition, if a Booster suddenly requires buying/extending during game play, you can have the tab frame do the quick-pulse.