To prepare glaze: In a small saucepan, mix together sugar and cornstarch. Stir in cranberry juice, vinegar, and soy sauce. Bring to a boil over medium heat. Cook and stir for 1 to 2 minutes, or until thickened. Cool while preparing the kabobs.
On metal or wooden skewers, alternate threading sausage, peppers, apple, and onion pieces. Grill over indirect heat, turning and brushing with glaze occasionally. Kabobs will be done when heated through (about 10 minutes).