10. Darkness (£0.59)
Use Darkness to know when the sun's going to vanish and be replaced by inky blackness, thereby avoiding vampires, werewolves, and killing yourself by falling down an extremely steep hill in Devil's Punchbowl. Not that this writer was dumb enough to nearly do the last of those earlier this year...
11. Flashlight (free)
Two for the price of one: use Flashlight at night to avoid breaking your neck falling down the stairs if you need the loo/a snack/to pretend you're burgling your own house; and use the strobe mode to distract ravers who are trying to mug you. When they start dancing, run like hell.
12. Sky Burger (£1.19)
As Elvis discovered, too many burgers can kill. Put yourself off eating burgers with the Sky Burger tower-stacking game. It's frustrating, so you'll hate burgers. And it tasks you with making burgers with about 50 lots of pickles, so you'll hate burgers. (Note: TechRadar takes no responsibility if this app makes you instead crave burgers, thereby eventually leading to an Elvis incident.)
13-14. 'stachetastic/80s Hair (from £1.19)
If you're on the run from the mafia/hit-men/your landlord, but out of ideas regarding a cunning disguise, grab yourself one of the apps from Work's Out. 80s Hair, 'stachetastic and Mulletizer (or the frankly scary 'stachetastic ULTIMATE) can have you digitally disguised in a matter of minutes. You then have the option of replicating the disguise or walking round holding your iPhone over your face.
15. Pianist (£2.39)
If UFOs descend, whip out Pianist, hope the occupants are like those friendly chaps from Close Encounters, and play the riff G4/A4/F4/F3/C4. If instead of returning abductees they proceed to blow things up with laser guns, mash the virtual keyboard like mad in a futile attempt to deafen our new overlords.