So I need to figure out a way I can store PDF files directly on my iPhone 7. These documents are generally user manuals for cameras and equipment i use when out shooting on locations. The reason I want to store them on my phone is that I don't always have cell or wireless access and need to consult the manuals periodically (we are sometimes down in canyons where wireless signals don't reach) so I may not be able to download them or use services like Google Drive or OneDrive at these types of locations. Now, I am aware of these USB flash drives from SanDisk that let you store files on it from your PC, and then attach it to your phone. Can you view documents with such a device plugged into your iPhone?