This is a brief overview showing how you can use the iMovie and Splice apps to edit your DJI footage on IOS.
Please check out my other video showing how to transfer data direct to your phone or tablet with the the cables included with the phantom 4.
I have not gone into depth using iMovie and splice, have a play with them to learn the features.
But iMovie to edit the movie, export to camera roll, open splice then your saved movie and add soundtrack, save to camera roll again