Smart Tools is a completepackage of 5 app sets. It includes 5 Pro sets for a total of 15 tools. In a word, All-in-One. Set 1: Length, Angle, Slope, Level, Thread - Smart Ruler Pro Set 2: Distance, Height, Width, Area - Smart Measure Pro Set 3: Compass, Metal detector, GPS - Smart Compass Pro Set 4: Sound level meter, Vibrometer - Sound Meter Pro Set 5: Flashlight, Magnifier - Smart Light Pro