iTunes has a Wish List. If you use the desktop version of iTunes, you may know this already. If you mostly use the iPhone, iPod touch, or iPad App Store, however, you'll be forgiven if you have no idea it exists at all. Because "add to Wish List", one of the features that makes the most sense on mobile, doesn't exist in the on-device App Store at all. And it really should.

Case in point, last weekend I received a text message from a friend who told me in no uncertain terms that Apple needed to add a "Wish List" feature to the App Store. She was out and about and came across something she didn't want to buy immediately, but really wanted to remember to buy -- or be gifted! -- at some later point. And not only couldn't she add it to her Wish List on the iPhone, the lack of functionality made her think iTunes lacked the feature entirely.

That's the perplexing thing about the Wish List, if you visit the App Store (or any other iTunes Store) on the desktop version of iTunes, you can click the little arrow next to the price of the app and click "Add to Wish List". If you visit the App Store on the iPhone or iPad, you're simply out of luck. The iOS version has no such counterpart.

Clearly, Apple has recognized a need for a Wish List, otherwise they wouldn't have included it in their desktop app, but for some reason they've decided not to include it in any of the iOS Stores. Your Wish List cannot be accessed from the App Store, iTunes Store, or iBooks Store on the iPhone or iPad.

Apple doesn't release metrics on where or how people buy apps, but I can't help but assume most people actually shop for iOS apps on iOS devices, and for them the current Wish List implementation is practically useless. We need the Wish List on the the devices we're shopping with -- our iPhones and iPads.

I use My Wish List all the time for Movies on the Apple TV. There are many movies I want to own, but don't have the money needed to purchase them all at once. Instead, I occasionally browse through movies in the iTunes Movies Store and add several movies to my Wish List at a time. Then once a month, I visit My Wish List and purchase one or two movies from the list.

I'm sure there are many people who would love to do the same with apps. Most people live their lives on a budget and don't have the means to buy every app they want whenever they want it. Teenagers who get an iTunes allowance or buy gift cards to add money to their account would also greatly benefit from a Wish List.

So let this be another plea to sit beside my request for a Kids category in the App Store -- please, Apple, give us Wish Lists in the App Store on our iPhones and iPads.