Smart Level is in the 1st set of the Smart Tools collection. This app measures the angle or slope of an object simply and accurately. Put the back of your device against a desk, or put its short/long side on a frame. * Main features: - Surface level (bubble level) - Spirit level (clinometer) - Zero calibration - Tilt units (degree, percent, radian, roof pitch) - Lock screen - Material design * Pro version added features: - No ads - Ruler, protractor, thread pitch * Do you want more tools? download [Smart Ruler Pro] and [Smart Tools] package. For more information, watch YouTube and visit the blog. Thank you.