What icon sizes should I give to IOS developers?

Question

iOS

It's only about iPhones. Made in Sketch design application.
I took the Artboard for iPhone 6 as a basis. I made custom icons for the navigation bar and cut them in the same Sketch.
I got the following three files (names from the bulldozer):
icon.png (22x22px)
[email protected] (44x44px)
[email protected] (66x66px)
I gave it to the developer, but he said that icons of the following sizes are needed:
44x44, 88x88 , 172x172
The following dimensions are indicated in the guide: The

question is, who is right?

Answer 1

In general, I was right.

Answer 2

just recently asked the same question to the developer =)
consider an example for 2x
icons in the navbar can be slightly different in width, for example;
so that when placing them they always occupy the desired position in the nav bar
and so that you don’t have to mess with each icon, you draw an icon of the required size,
and when cutting it, set it on a transparent background 88px / 88px;
in this scenario, when developers push them into the code,
all the icons will sit in the right place