iPad is not showing in Develop menu on OSX Safari
Solution 1:
Enable web inspector on your iOS device by following these steps:
iOS Device
> Settings app
> Safari
> Advanced
> Web Inspector
This setting allows you to connect to safari on your desktop.
Solution 2:
I know this is a little late. I had this same issue and figured I would post how I got it to work in my case just in case it helps anyone in the future. I enabled it on the iPad and it didn't show. I tried closing Safari on the iPad, disconnecting and reconnecting the cable and neither worked. It ended up for me being really simple, I just quit of Safari on my laptop and restarted it and Safari then recognized the iPad and allowed me to debug. This may not work for every case but it did for me, hope it helps.
edit: just a note, I had the iPad plugged in with web inspector enabled when I restarted Safari.
Solution 3:
In my case I was running iOS 11 BETA on the iPhone, and was trying to access from Safari 10 (current stable version). I have installed Safari 11 BETA, and now it is working as expected.
So in general: Make sure you are running the latest version of Safari. And if you are testing on iOS BETAs, you can download Safari Betas & Safari Technology previews from here (Thank you for the link @Jacob Ford).
Solution 4:
You also need to enable web inspector from the device.
Open the settings app, select safari, select advance and then turn on web inspector.
ref: http://www.spiraltrack.com/blog/how-debug-iphone-and-ipad-web-applications-using-safari.
Solution 5:
Using a genuine Apple lightning cable (instead of a fake one) solved my problem.