Besides navigation, over the ground, it could give you ground speed read out, elevation and help in computing bombing equations. This is very difficult science to do manually, so this little device, when it worked properly would aid in keeping you oriented and proficient at hitting targets. Its flaw was that it was very, very finicky. It wanted to be constantly reassured as to its true position.
I thought it was really neat, cause, what it was actually doing, was driving a small motor that moved a transparent film strip In two dimensions with a light behind the strip to give it visibility. The transparencies were pieced together pictures of a map covering the entire USA. Literally, someone had taken a camera, snapped pictures of all the current maps and made them in a film canister, driven by a gyroscopic Inertial Navigation System. It was brilliant, for its time.
Of course now today it sounds very funny, but bits and bites had not really come to age, so… no digital. Didn’t exist. Pretty clever way to do digital without digital!