iPhone

• iVegan: has ingredients, alcohol, animal testing and more
• Animal-Free: lists animal ingredient names
• Cruelty-Free: lists a variety of products (make up, cleaning, etc...)
• VegWeb: access the vegweb recipes from your phone (very nice interface)

Alcohol

• IsYourBeerVegan
• IsYourWineVegan
• IsYouLiquorVegan
• VeganIsEasy: this one includes beer, wine and liquor and shows emails from the companies confirming whether they are vegan or not. But it has a much smaller list than the previous three

All the apps I mentioned are free and do not require data except the VegWeb app. That one needs internet and costs $2.99

There are probably lots more. I haven't looked in a while.

Android

• Animal-Free: lists animal ingredients and some ingredients that are "always" safe
• VegeTipple: search for your specific alcohol to find out if it is vegan. Very detailed list. Works offline.
• What Additives: list of additives and whether they are vegan and some other information
• Cruelty Free: brands that are cruelty free (no animal ingredients or testing)
• Choose Cruelty Free: another apps listing cruelty free brands
• Veg Check: With this app you can scan a barcode and it will tell you if the item is vegetarian, vegan or not. Link no longer works.

There are also lots of recipe apps for both android and iphone as well as apps for specific cities and books.