We just bought a fixer upper and this little tool has been a huge time and material saver. If you've ever tried to do any home repairs, you know nothing is ever plumb or square. Especially in older homes that have had time to settle.
So far we've used it for measuring angles to lay tile in the bathroom, laminate flooring in the living room, and crown molding. I can't even begin to tell you how helpful this little baby is for that! This ranks as one of my most useful tools, right up there with my tile saw!