I'm making this for my Sunday school students this week. I saw it done at camp a couple of months ago and the kids there loved it! Works wonderful for a fruit of the Spirit tree!
My lesson is about how God takes care of us giving us food, and I thought the kids would enjoy taking this apple with the memory verse reference home...
Blow up the red balloon to about the size of a good-sized apple and tie it.
With your pointer finger, poke the nozzle of the balloon toward the other side of the balloon.
Grab the nozzle of the balloon tight and twist it a couple of times, tie with the green balloon.
Wrap the green balloon at least twice around to make sure it holds steady.
You then can remove the finger from the middle of the balloon and adjust minor things like squeezing air around from a bulging side so the apple looks nicely shaped!
Super easy, isn't it? And I'm sure the kids will be very pleased with it!