Because the first time you need this app can't be the first time you use this app!Think about that for a moment. Can you count on having your mobile device in a real survival situation? Does it have a full battery charge? Was it damaged in an accident? Was it submerged in water? In a real survival situation you will be under tremendous stress. Is that really the time to use an app for the first time? This app is designed to help you become familiar with basic survival skills BEFORE you need to use them. It is the only survival app presented as a study guide. It contains 800 questions! You can track both your study and test progress at a mere glance.This app is perfect for studying survival "15 minutes at a time." You do not have to worry about keeping track of what you have or have not studied. The app tracks that for you.Look, if being prepared is important to you, go ahead and buy several of the other apps from other developers too. You can buy all of them and still spend less than you would at a fast food restaurant for lunch.