On the app:
Select Add device
Top of screen, select Add Manually
Select ITC-308wifi from the list of device options
Scroll down; input / confirm your wifi SSID (name) and password
Select Next
At the top right of the screen ensure that EZ Mode is ticked
On the Controller:
At this point you need to ensure the wifi LED on the controller is flashing rapidly. See below for instructions how to do this:
To make it flash first of all, press and hold the wifi / up arrow button for +2 seconds.
At this point you can toggle it between flashing fast and flashing slow.
If it's flashing slow, short press the wifi button and release. APP will be displayed on the LED, but the flashing will not change until after the count of 5. Wait for the 5 seconds and it will start flashing fast. (This is (Auto / EZ mode.)
If it's flashing fast, you're good t go. You can toggle to the opposite by repeating the above: short press the wifi button and release. APP will be displayed on the LED, but the flashing will not change until after the count of 5. Wait for the 5 seconds and it will start flashing slow (This is AP mode.)
Do whatever is necessary above to have it flashing fast (Auto / EZ Mode)
Back on the App:
Select the circle next to "Confirm indicator rapidly blink" (sic) so that it has a tick in it
Select Next (and make sure wifi LED is still flashing fast on the controller)
Adding Device is displayed
Then with any luck:
Added Successfully will appear
Select Done
You can now connect to the controller from your phone and set all the good stuff without fannying about with the buttons on the controller itself.
Separately, one thing I noticed when I was configuring it; when you go into settings and you change something, you have to select <-Back in the top left hand corner to save the settings. Don't click the back arrow on the bottom of the screen. I have an Android mobile phone so I'm not sure what is displayed on iOS.