This app should be used for baking / cooking. It is a handy tool but not as precise as a real jar or scale.
This app should not be used on anything other than flour for making bread, milk in a milkshake or yoghurt for your cereal and likewise stuff.
Always use your common sense, if you need a very small amount of something and the scale or jar says you will have to fill a relatively large container half full, you probably did not calibrate the app or the container correctly.
Always be careful with every product you use while baking or cooking, even real common ingredients like nutmeg can be dangerous when used in large dosses.
Never use for medicine, mixing baby powder, chemicals or anything requiring more precise measurement.