Allergy Free App for iPhone or iPad

I just saw this app here that sounds really helpful.  Here is what it says it can do. Note: you need to go to their site to buy the app.

Custom Tailor Any of the Recipes

• Hundreds of Gluten Free recipes that can be customized to meet most Food Allergy needs
• More recipes being added all of the time
• With a simple tap, trade out your Allergen(s) in any of the recipes with safe substitutions. Now no recipe is off limits!
• Find substitutions within the recipes for: eggs, butter, milk, yogurt, buttermilk, cream, sour cream, cream cheese, cheeses, nuts, nut butters, corn syrup, and soy.
• Customize your recipes and then share them through Email, Facebook, and Twitter.
• Find great tips for allergy free cooking that will help to give you delicious results.

Custom Tailor Any of the Recipes

• Save your recipes to your Grocery List and have all of the ingredients you need, including your substitutions for your allergens, at your fingertips.
• Your list will be organized by Aisle or by Recipe. Add items from your daily list as well.
• Check off items as you shop single ingredients, entire recipes, or your entire list with
  simple taps.
• Your custom-tailored recipes can also all be saved in one place: Your Recipe Box.
• Keep your own notes within each recipe to remind yourself of what you liked or didn’t like
  about your results. Allergy Free cooking is all about “trial-and-error”

For common allergens like eggs, butter, milk, yogurt, buttermilk, cream, sour cream, cream cheese, cheeses, nuts, nut butters, corn syrup, and soy.