Saponify

An easy to use, soap-making calculator and recipe storage app. Takes the math out of soap-making by providing a full-featured lye and lipid calculator. Allows you to calculate by ingredient percentage or weight, use both had and soft soap lye, add custom ingredients, and more. Also includes a handy saponification value lookup chart if you want to do the calculations on your own.

After you've calculated a recipe, you can save to your recipe collection for later, and even modify that recipe if you want to change the ingredients, or make a different amount of it.