If your App consumes files, you'll need to figure out how you want your users to get their files to your App. For iOS applications you essentially have 3 options. 1. File Type Association 2. iTunes 3. Various Cloud Services (DropBox, Google Drive, SkyDrive, Box.Net etc...) In this article I will will walk you through the first option and i'll be breaking it into 3 parts. The first part will be using known UTI's (Uniform Type Identifiers), such as PDF. The second part will be registering your own file extension. And the third part will be showing you where to find the files you opened. Before we get started, let me explain what i mean by "File Type Association". Basically, in iOS your App can register itself as a source for specific File Types.