Two uses of convex mirror:

1) Convex mirrors are used inside buildings:

Large hospitals, offices or stores sometimes make use of convex mirrors in order to let people see what is around a corner to avoid people running into each other and prevent minor/major collisions.

2) Convex mirrors are used in vehicles:

They are used as a rear view mirror in vehicles because the mirror can diverge a beam of light and makes a virtual image. And as the focal length and radius of curvature of the convex mirror are virtual the image is always produced up the right way and that too smaller in size than the actual size of the object. So the mirror is able to give a wide view of the field.