The wijmaps widget allows you to add parallels and meridians to the map. Meridians represent degrees of longitude, and also shows the distance of a place from the prime meridian, and Parallels represent degrees of latitude, and distance from the equator. Using such maps enable you to find out exact location of a particular place.
You can use the vector layer on top of a Tile Source to draw geometries, shapes, polygons, paths with geo coordinates.