Many retailers, for instance, will match deals you find elsewhere, so these apps can help you find better prices to show the cashier. Some let you search for coupons, while others tell you whether you're better off buying online instead. And one keeps track of all those promotional fliers that do little good if you forget them at home.
I tested more than a dozen shopping apps - in the process getting some of my holiday shopping done early. I narrowed the list to five because using them all at once can get time consuming. You want to beat others to the best deals, after all.
Unfortunately, If you prefer to shop at mom and pop stores, you won't find any deals here. But if you don't mind big retailers, these apps offer a hefty selection of deals from them. The ones I chose are all free, easy to use and beautifully designed.
RetailMeNot (Available for Android, iPhone)
This app lets you search for coupons from your favorite stores, so you can instantly save 10 percent, 20 percent or even more on a single item or your entire shopping cart.
You can scroll through the list of hot deals on the home page or search for a specific store. You can add your favorite stores to a list to see the deals more quickly. The app uses the phone's location information to narrow the deals to the ones near you.
I'm not saying these apps are problem-free. At Toys R Us, the cashier wasn't able to scan a 15 percent off coupon. RetailMeNot says many retailers have outdated scanners, but most will honor the discount anyway. That happened at Toys R Us after the cashier called for a manager. Getting the discount took longer than expected, and some people in line behind gave me bad looks. But the deal was worth it.
The app lets you see both in-store and online deals. After walking into a Gap retail store, I found a coupon that works only online. So I left and went to Gap's website. RetailMeNot's 35 percent off coupon code saved me $20.26 on a $57.89 purchase.
If you create an account, you can browse for deals on RetailMeNot's website. Any coupons you save on the website will show up on the app. They will delete when they expire.
One annoyance: According to RetailMeNot, about a third of the coupons are uploaded by users. Employees go through them to make sure that they work, but some bad ones get through. About a month ago, I went to Gap with a coupon that didn't have an expiration date. But after the cashier called a manager, I was told it expired a week earlier. RetailMeNot says such problems are rare. To me, the savings from this app is worth the small inconveniences.
Amazon and RedLaser (Available for Android, iPhone, Windows)
Many retailers, including Best Buy Co. Inc., Target Inc. and Toys R Us Inc., are promising to match cheaper prices you find online, hoping you'll buy on the spot and not wait until you can get to Amazon's website.
To take advantage of that, install Amazon.com Inc.'s app on your phone. You can scan barcodes of items in the retail store and see how much it costs on Amazon. If you find a better price, show the app to a cashier. I've gotten cashiers at Best Buy, Target and Toys R Us to knock off as much as $10 on different items. The savings can add up.
The RedLaser app, which is owned by eBay Inc., searches several online retailers, giving you more chances to find better prices than if you just searched Amazon.
RedLaser doesn't search Amazon, so use both to make sure you are getting the lowest price.
Cartwheel by Target (Available for Android, iPhone)
I tried apps for several retailers, but Target's was the best. Cartwheel is easy to use and has coupons for everything from electronics to toys to cereal.
You can search for coupons by category as well as "collections," such as items to help ease a cold or holiday decorations. Once you find a coupon you want to use, you tap the add button. Then present the cashier with a single barcode that has collected all the coupons you selected. These coupons don't work online, only inside Target stores.
The best part is that they can be used on top of other coupons you may find elsewhere. That can increase your savings a lot.
Flipp (Available for iPhone)
I never remember to save retailers' promotional fliers that come in newspapers, even when I come across one that's tempting to use. They're hard to carry around, and they usually end up in the trash.
The Flipp app can help. Flipp works with retailers and turns fliers digital. The digital version is identical to the paper one, and you can flip through it with a flick of your finger. You can also search by a store's name and digitally "clip" deals you want to save.
If there's a store you shop at often, you can have new fliers automatically appear.
While at Macy's, I found a flier that offered $10 off a $25 purchase. Several people ahead of me in line had the coupon cut out of the paper flier. I gave the cashier the coupon from the Flipp app.
You can also use the app to build a shopping list or compare prices from different stores.
Unfortunately, there's no Android version yet. The app just launched in November.