The ornamental design for an applicatortool, as shown and described.
FIG. 1 is a perspective view of an applicator tool showing the new design;
FIG. 2 is a front view thereof;
FIG. 3 is a side view thereof;
FIG. 4 is a top view thereof; and,
FIG. 5 is a bottom view thereof.
The broken line showing of an applicator head is included for the purpose of illustrating environmental structure and forms no part of the claimed design.