It creates a uv map template from an object. Uv map templates are the flattened out 2d versions of the 3d object, you use them to paint textures. UV Mapper can also be used to fix some kinds of errors and to encode .uvs files. For starters you'd mostly be interested in the first part. Most times figures and objects come with uv maps already made.

"Your work is to keep cranking the flywheel that turns the gears that spin the belt in the engine of belief that keeps you and your desk in midair."

Annie Dillard