Please explain in more detail what you want to achieve. Do you wish to view documents in a native app? Or pick a document on the device?
Anyway, my native file documents module can probably help:
Read the documentation carefully! You need to create a custom build, you cannot use the Make it Native app for this.
Edit: You can use the TakePicture or TakePictureAdvanced to take a picture using the camera or select one from the image library. These are in the NativeMobileResources marketplace module.