The ornamental design for a wall mount apparatus, as shown and described.
FIG. 1 is a perspective view of a wall mount apparatus showing my new design where the wall mount apparatus is fully extended;
FIG. 2 is a perspective view of the wall mount apparatus where the wall mount apparatus is fully retracted;
FIG. 3 is a front elevational view thereof;
FIG. 4 is a rear elevational view thereof;
FIG. 5 is a left side elevational view thereof;
FIG. 6 is a right side elevational view thereof;
FIG. 7 is a top plan view thereof; and,
FIG. 8 is a bottom plan view thereof.
The broken lines immediately adjacent to the claim depict the bounds of the claimed design, while all other broken lines are directed to environment. The broken lines form no part of the claimed design.