Any flavor of gelatin can be used, also the same for the yogurt. The pie shells can be either Graham, Vanilla, or Chocolate. I use the 12" ones because I like to add about an ounce of fruit.
In a mixing bowl, dissolve the jello in the boiling water. Add the yogurt, blend well, then add the whipped topping. Fold together until well blended and pour into the pie shell. Place in the refrigerator. I like to make it a day ahead of time, because it taste better after it sits for awhile.