When switching from Samsung to iPhone you must need to copy important data from Samsung to iPhone. Here is a video about transfer contacts from Galaxy S4 to iPhone 6S with one click, just have a try.
Watch The Video:
http://www.youtube.com/watch?v=67EDiDrhasU
Moreover
> Transfer more data such as SMS messages, photos, music, videos and more
> Works with more phones from LG, HTC, Motorola, Nokia, BlackBerry, etc