I downloaded the Red Cross First Aid app on my Android phone, and it's largely useless for through-hikers. Nearly every set of instructions ends with "call 911". They have helpful questions and answers like "What if I don't have any ice?": "Use frozen vegetables instead". In short, its instructions require that you be in civilization with a phone signal, refrigeration, running water, and the like.

Are there any first aid guides that are of use on the trail?