If you want a new experience in doing your nails, Fingernails2go might be the great option. Fingernails2go uses the nail-art design printer machine that could instantly print the patterns you select or your own uploaded photos on to your nails, and you could choose between gel nail or basic manicure finish. They have both offline store, and a pop-up store with just the machine placing at different places such as the CGV Theatre.
Where to find them?
Currently, they are many shops scattered around Seoul (other than the Gangnam branch) and other cities in South Korea, so pick whichever branch is the most convenient to your place! Check their website [here] for a list of their available stores!