Answer:
What does a WW1 Trench, A Submarine and a Popular Phone App all have in common?
Useful tool for who in darkness dwell. Within you, corrupting like a deadly spell.
The French word for 'fun size' in women's clothing.
Someone walked into a room and you heard a crash! Someone died. What happened?
Turns us on our backs, and open up our stomachs. You will be the wisest of men though at start a lummox.
Almost everyone needs it, asks for it, gives it. But almost nobody takes it.
Difficult
Animal
Easy
Food
Funny
Kids
Logic
What am I?