In a Dutch oven, brown chicken over medium heat in oil in batches on both sides; drain. Return all of the chicken to the pan.
In a large bowl, combine the water, brown sugar, soy sauce, apple juice, ketchup, vinegar, garlic, pepper flakes and ginger; pour over chicken. Bring to a boil. Reduce heat; cover and simmer until a thermometer reads 170°-175°, 20-25 minutes.
Remove chicken to a platter and keep warm. Combine cornstarch and water until smooth; stir into cooking juices. Bring to a boil; cook and stir until thickened, about 2 minutes. Serve with chicken.