What a Godsend!
Upgraded from a 5S to a 6S and everything went fine except for my contacts. Not even half of them transferred in the restoration. I was getting so frustrated. This was the first time Ive upgraded an iPhone and I didnt know what to do. I found this app, its free and so easy. It worked perfectly! All my contacts are transferred (I only had to delete about four dupes).
pmpmn about
Copy My Data - Smart Transfer, v1.23