Soak wooden skewers in water for 1 hour. In grill with cover, have an adult arrange preheated coals around drip pan for indirect grilling.
For sauce, combine apple jelly, lemon juice, and cinnamon in a saucepan. Cook over low heat, stirring occasionally, until smooth and bubbly. Remove from heat; set aside.
Cut pineapple into 1-1/2-inch pieces. Thread pineapple, strawberries, nectarine wedges, and cake cubes alternately onto skewers, placing kiwi halves on each end. Leave a little space (about 1/4 inch) between each piece so heat can go all around. Transfer kabobs to a baking sheet or tray so you can carry them easily to the grill.
Place kabobs on grill rack over drip pan.
Cover grill. Grill kabobs 2 minutes. Carefully turn skewers over. Use oven mitts to protect hands.
Use a long-handled brush to slather some of the sauce over kabobs. Grill for 1 to 2 minutes more or until heated through. Turn. Brush with sauce. Remove kabobs from grill.