You can measure the length, angle, distance, height, direction.
Smart Tools is a toolbox of a collection of 1-4 series. It includes 4 Pro versions that have 14 tools. In a word, All-in-One.

Part 1. Length, Angle, Slope : Smart Ruler & Protractor Pro

Part 2. Distance, Height, Width, Area : Smart Measure Pro

Part 3. Direction, Metal detector, GPS : Smart Compass Pro

Part 4. Sound level meter, Vibrometer : Sound Meter & Vibration Pro

For more description, see the manual for each of the apps and visit the blog.