Hi Karey,
Yes, that's correct, but there are a couple other sizes, if I'm not mistaken.
This is very informative:
https://developer.apple.com/library/ios/#documentation/UserExperience/Conceptual/MobileHIG/IconsImages/IconsImages.html#//apple_ref/doc/uid/TP40006556-CH14-SW2Read the section "Application Icons" for details. It explains what I mentioned to you in my previous commment.
You only need to submit the logo mark at the dimensions Apple requests, and they take care of turning it into an icon for you, specifically for displaying on the App Store, and on the devices (iPhone, iPad). Again, if you want your logo mark to consist of a rounded cornered, square (that looks like an app icon), then that can be achieved, but I just wanted to let you know that it's not required. Clients often think you have to design an icon for their logo.
Just to make sure you understand my terminology:
1.) Logo Mark - This is the pictorial mark / design.
2.) Logo Type - This is the type, or font use to display your business name
3.) Logo - Both your logo mark and your logo type as a whole