2 carton beaker, 1 piece of cardboard tube, 2 piece of toilet paper and 1 piece of toothpick
Cut a slit for the smartphone in the cardboard tube. Stick the toothpick in the middle of the tube to hold the phone on the half height of it. Form two balls with the toiletpaper and poke one in each side of the tube. Cut holes in the carton beaker and put the tube in it. Glue all together.