In a cocktail shaker, add lime juice, rum, simple syrup, fresh mango and mint. Muddled ingredients together and break up mango. Add 1/3 cup of ice, cover, and shake well. About 10-15 seconds. Uncover the shaker, keeping the strainer on, and pour cocktail into fine mesh strainer over your prepared glass (filled with ice). Top with sprite/sparking water and stir slightly to incorporate. Garnish with a slice of lime, mint leaves, and a slice of fresh mango.