If I would be left on a desert island with those things, I would turn off the phone in order to save the battery for when I need it later, I don't think that I would have any signal there. I would open the parachute and try to make some sort of bed out of it. With a butter knife I could try to hunt some fish in the water, there should be enough fish for ten years. With the matches I would make fire for the night, or for when an airplane or helicopter gets near. But I am sure that I will never end up on a desert island.
