The ornamental design for a armbandholder, as shown and described.
FIG. 1 is a front perspective view of the present invention in a flattened condition.
FIG. 2 is a front elevation view of FIG. 1.
FIG. 3 is a top plan view of FIG. 1.
FIG. 4 is a rear elevation view of FIG. 1.
FIG. 5 is a bottom plan view of FIG. 1.
FIG. 6 is a left side elevation view of FIG. 1; and,
FIG. 7 is a right side elevation view of FIG. 1.
No claim is made to the interior surfaces of the armband holder, the strap portion, the inner pocket, or any part that is not shown in the images. The phantom and dashed lines in the views form no part of the claimed design and reflect either disclaimed portions of the invention, including the retaining strap, inner pocket and pocket-mouth opening, stitching on the piping, and back side texture nubs, and the surfaces are lightly lined as an illustration aid.