From the Wikipedia article on the Liahona:
According to the Book of Mormon and other Latter Day Saint movement sources, the Liahona (/ˌliːəˈhoʊnə/) is a brass ball that operated as a type of compass with two spindles. One of the spindles was said to point the direction Lehi and his party should travel after their escape from Jerusalem, but it only worked when they were faithful. The Book of Mormon states that the Liahona also contained periodic written instructions from God. According to some sources, the Liahona was among the Book of Mormon artifacts Joseph Smith said were found with the golden plates.
As Depicted in Book of Mormon AR
The 3D model has two spindles: one points north, and the other points to various landmarks having to do with the Restoration. The model can be open or closed by tapping on the top half of the model.