Realtor and Professional House Flipper Bobby Curtis played a game with Tra' called "What Does This Tool Do?" Click here for more information about Bobby.
Stud finder: find a stud in a wall so you know where to anchor a wall fixture, or where you have space to add a vent
Staple lifter: good for pulling the staples from the floor after you pull out the carpet, in prep for refinishing wood floors.
Wood shaver: (great for peeling paint and stripping down a door that was freshly painted and now won’t shut
Non-contact voltage detector: Is that wire hot?
Putty knife: to apply drywall compound, but I love to use this with a hammer to crack open windows that have been painted shut. Stick the edge in the crack that's painted shut, and gently hammer the end to break the seal.