This set of instructions is for transferring files and controlling a Sony A7 series camera with the iPhone, as of September 2018
On your iPhone, download the PlayMemories Mobile app [link to App Store]
On the Sony camera, power on and go to the Menu > Wi-Fi Panel (Wi-Fi icon) > Screen 1 > Airplane Mode= Off

To control the camera from iPhone:
On the Sony camera > Applications Panel (Grid icon) > Application List > Smart Remote Embedded
(After a few seconds, a screen displays the SSID (the Wi-Fi network that the camera is setting up) and password)
Leaving the camera displaying this screen, go to your iPhone > Settings > Wi-Fi, select the camera’s SSID and enter the password displayed on camera screen (you should only need to do this once)
You will see a ‘connecting…’ message on the camera
Open the PlayMemories app and you should now see the camera’s viewfinder displayed on your phone.
To disconnect, Exit the Smart Remote Embedded app by pressing menu and following screen directions

To Send image files between camera and phone (in either direction):
On the camera > Menu > Wi-Fi Panel (WiFi icon) > Screen 1 > Send to Smartphone and select options
When you see the ‘Operate smartphone to connect to this device via Wi-Fi’ go to your
iPhone > Settings > Wi-Fi > select the camera’s SSID
Images will transfer and be moved to the Photos app on iPhone
Powering off the camera will disconnect the wifi.