Boil 1 cup of water. Set out a large heat-proof liquid measuring pitcher. Add the jello mix, sugar, and salt. Then pour in the hot water and stir until the mixture is completely dissolved.
Now pour in 1 cup of cold water. Stir well.
Carefully pour the jello mixture into the popsicle mold. Place the lid over the top and insert the popsicle sticks into each slot. Freeze for at least 4 hours, until the frozen jello is solid.
To remove for the mold, turn the mold upside down and run warm water over each cavity for 30-45 seconds. Gently pull out the pops. Serve immediately.
For Rainbow Jello Pops: You can layer as many colors and flavors as you like. Just remember each box of jello with multiple to total amount of popsicles by 10. For instance, three flavors of jello will make 30 popsicles, so be sure to purchase plenty of molds. Making rainbow pops takes a little more patience, because you need to wait for the first color to set before adding the next color. Place each layer in the freezer for approximately 30 minutes until the jello is firm, then make the next batch of jello to pour over the top. Once the final layer is on top, freeze for 3-4 hours.