A device and method for applying decals to fingernails or toenails involving a substrate and a plurality of decals temporarily affixed to a bottom surface of the substrate, wherein the substrate includes a central body portion, a plurality of stem portions extending outwardly from the central body portion and a decal application tab portion extending outwardly from each of the stem portions. There may also be a graphical user interface, including a virtual instrument positioned substantially at a top portion of the graphical interface. Kits comprising components for carrying out the methods and instructions for use are also provided. Superimposition of the first treatment zone and the one or more additional treatment zones defines a non-continuous circumferential treatment zone without formation of a continuous circumferential lesion. The system is configured so that two or more separate drug delivery devices can be acted upon at the same time.