When setting up your scope, or preparing to take naked-eye observations it is very important to know the direction of South (or North in the northern hemisphere). As skilled backyard astroscientists we can navigate by the stars right? But even we need a compass to help do an initial setup during the day, or on a partially cloudy night when all the stars are not visible.
Often a mobile phone app can be used as a compass, but always be aware of any settings that relate to “True North”. Magnetic North and True North differ by over 10 degrees in Australia!