I don't keep lots and lots of apps on my devices. I just keep the ones I actually use. Browser, Maps, Tapatalk, a couple of news/weather apps, BusinessCalendar...
I do use
ColorNote to keep track of my "to-do"-lists that aren't calendar stuff.
And my most favourite app of all:
MotoGp Live Experience! Probably not something many of you would even consider paying $25 for, but for a long time MotoGp fan like me it's "essential" (well, not really, but cool anyway...
)