In digital couponing, one company is King Kong, Godzilla, and Jaws all rolled into one.

If nearly any other company released another coupon-based mobile shopping app it would be less than newsworthy. However, when that app is the product of the company that controls 90 percent of the digital coupon market, has the 49th most visited website in the US, and is hell bent on extending its dominance beyond the Web into mobile, it warrants discussion.

The app in question is the smart shopping list Grocery iQ and if you know anything about digital couponing, you already know that the company is Coupons.com. The company made more than $90 million in revenue last year and raised its latest $200 million financing round at a valuation of $1 billion (with a “B”). That’s real deal business territory.

Coupons.com is built on the fact that a vast majority of grocery shoppers use some combination of coupons, traditionally clipped from the “Sunday paper,” and loyalty card rewards every time they shop. At the same time, a comparable majority make shopping lists before heading into the store. The numbers quickly grow staggering, with hundreds of millions of consumers receiving hundreds of billions of coupons per year.

So why the hell has it been so difficult to make a shopping list app that offers these same physical coupon benefits while adding the additional value promised to accompany the transition to mobile?

A new version of the Grocery iQ app for iOS was released today seeking to answer this question. (An Android updated is expected in June.) The app, which has long allowed users to build and share digital shopping lists, has added some notable new features and reconfigured some old favorites to make the overall functionality better and more enjoyable. As to be expected with its parent company association, the app includes a fair helping of coupons as well.

The new version divides list-making into two categories, the previously available “List by Store” (e.g. Safeway) and the newly added “List by Event” (e.g. Friday Dinner). In addition to the ubiquitous predictive text-based and barcode scanning methods of adding new items, the app now supports voice dictation. In theory, the software supports adding multiple items continuously through both dictation or barcode scanning, without interruption. This is true until you ask Ozzy Ozbourne to help you dictate a list (see 3:42 of this video).

The updated app also now incorporates shopping histories and favorites, such that if a particular brand of beer is purchased regularly, the next search for beer will highlight offers related to this brand. Alternatively, if shoppers are less brand loyal, the app will offer the coupons providing the best value within the product category.

Once a list is built, the app now can batch related items by aisle or section, such as those in the “bakery isle” or the “dairy section,” for more efficient shopping. Thank God, because a map of the route a typical man takes around a grocery store looks a bit like a Jackson Pollack. Finished lists can be shared to other mobile devices or to the Web where multiple users can update them to add new items or check off purchased items.

Beyond the addition of these fancy new features, the app has gotten an overall facelift and a few UI improvements to better highlight the most used features. Having used several similar apps, I’d conclude that it looks well thought out overall, although more time in the in the pantry and grocery store aisles would be required to pass final judgement.

Coupons.com declined to release user statistics for its app, only saying that there are millions of downloads and a very active user base which use the app an average of three to four times per week. Additionally, betweeen Grocery iQ and its Coupons.com app, COO Brian Weisfeld says, “We can confidently say that we provide the world’s most downloaded online, Facebook, and mobile couponing applications.”

In addition to powering its own mobile apps, the company has begun “white labeling” its couponing engine to power the apps of other ecommerce platforms. While it wouldn’t openly disclose the names of its partners, they’re known to be among the world’s biggest retailers and consumer product groups.

There are certainly competitors in the space, such as Coupon Sherpa, Our Groceries, or even Aisle411, which geo-locates items in stores and offers recipes based on purchased items. These are but a few of the would-be kings of this market, with several dozen more likely being cooked up as we speak. Ultimately, these apps succeed only if they do two things well: make creating shopping lists and shopping easier and more enjoyable, and offer discounts that make staying within budget a reality.

The new version of Grocery iQ offers a strong feature set and an increasingly intuitive design. Most importantly, it has a rich and powerful daddy in Coupons.com that is committed to seeing its progeny succeed.