I thought Safari was the only browser on iPhone.
But the "Mozilla Compatible Agent -iPhone" stats are 3 times
greater than "Safari -iPhone" in my Google analytics.

What's the story?
I heard one rumour that the MCA - iPhone stats are for
jail-broken phones but the numbers seem too far out of
whack to believe that.

Safari often "identifies" itself as "Mozilla 5.0" or "Mozilla compatible" and has done for 5 or 6 years.