That's plenty of free space. Do you have Time Machine running on an external drive? If not, that is foolish. It's brain dead simple to run and keeps a current copy of your system at all times.
Never heard of that app before...
Some drives are just naturally chatty.

"If it turns out that President Barack Obama can make a deal with the most intransigent, hard-line, unreasonable, totalitarian mullahs in the world but not with Republicans? Maybe he’s not the problem."