iTunes link: FileApp - £Free
The sizeable amount of storage built into all the iPhone models means they’re ideal tools for carrying files around on. This is where FileApp comes in, as it makes it easy to transfer files from a PC to your iPhone. You can connect to your phone from your PC either via a USB cable or over Wi-Fi as long as they’re on the same network.
Once connected you can simply drag and drop folders and files across to your phone. You can then sort your files by filename, date created or file type. Naturally, you can also view files while they’re on your phone. A pretty wide range of file formats is supported for viewing, including Word, Excel and PowerPoint, along with PDF, HTML, TIFF and JPG.
FileApp is a pretty simple application, and it makes it easy to get files onto your iPhone and then view them.