A flexible under-nail support device and method to apply the same that promotes long healthy fingernail growth by providing nail strength and support without any interaction or damage to the nail plate (upper nail) or the hyponychium (thickened epidermis under the nail). The device has an indention, with a preferred embodiment of an inverted V that is positioned under the fingernail and around the hyponychium. Its lateral sides are bonded to at least the nails' lateral undersides to provide extra strength to the nail. The bonded device is then clipped and filed to the natural nails length. The method includes healthy easy device removal and support replacement. As the nail grows, the process of attaching and removing supports is repeated and over time results in strong, long, healthy, aesthetically pleasing nails. For immediate nail lengthening, the device may be used as scaffolding with other technologies mitigating their respective health hazards.

A fingernail sleeve device for enwrapping both the finger and the elongated decorated fingernail includes an opening. The opening is circular and is coupled to a surface. The surface has a finger side and a nail side and enwraps the end of a finger. The nail side is positioned upon the fingernail of the finger, and the finger side is positioned against the skin. A cavity protrudes out from an end of the surface and has a downward curvature. An elongated decorated fingernail is nested within the cavity. The cavity defines an enclosed space for the fingernail. The cavity and the nail side of the surface have a hard material to protect the fingernail within the fingernail sleeve device. The soft material facilitates the application of the fingernail sleeve device to the finger.