Comic Zeal, File Browser, 2 Factor apps (Google Authenticator, Steam auth, etc), Google Maps (eff a bunch of Apple Maps), Cloud tools (Dropbox, Google Drive, OneDrive)...That's about it for my must haves. I also like to have some other apps but use them less frequently (Sudoku, guitar-based apps (tuners, chord charts, etc), Game strat apps, Cyanide & Happiness, Dark Sky, etc.