Nail glue is a type of adhesive used to adhere fake nails to your own. Once applied the glue doesn't come off until you soak your nails in a solution that dissolves the adhesive. Nail glue spills and smears that occur on your phone bond quickly with the surface the same way super glue does. It's important to remove the glue to avoid getting it stuck to your fingers or any other surface. This must be done carefully so the adhesive is removed without damaging the phone.
Allow the nail glue to harden on the surface of the phone. Attempting to wipe it off while it's still soft can result in spreading the adhesive further. File the hardened nail glue with an emery board to wear down the glue as close as possible to the surface without rubbing against the phone.
Wear rubber gloves to protect your skin from irritation. Wet a cotton ball with acetone and squeeze out the excess.
Wipe the remaining nail glue stain with the acetone-dampened cotton ball. Continue to wipe as the adhesive softens and lifts from the surface. As the glue is removed change to a clean cotton ball and continue to wipe until the nail glue is gone.
Dampen a clean cloth with warm water and add one drop of mild soap. Squeeze out excess moisture from the cloth before wiping the surface of the phone to remove the acetone. Rinse the phone by wiping it with a damp cloth then dry with another cloth.