The Church of Jesus Christ of Latter-day Saints

This is a fantastic question! I encourage you to read the Book of Mormon to find out for yourself - it's free online. The Book of Mormon actually doesn't have many unique doctrines - in fact, it isn't supposed to. The purpose of the Book of Mormon is to serve as a second witness that Jesus Christ is our Savior (see 2 Corinthians 13:1), not to teach any new doctrine. It shows us that the Gospel is for all nations, not only those in the Holy Land. The Book if Mormon does help to clarify some Biblical teaching on such topics as resurrection, the relationship between faith and works, the purpose of the Law of Moses, prophets, revelation, and the eternal nature of Jesus as the Son of God. The most defining feature of the Book of Mormon is of Jesus Christ visiting the ancient inhabitants of the American continent shortly after His Ascension.