Check out these smartphone applications for shopping in the holiday season. All are free and have versions for Android and Apple devices.

ShopAdvisor, by Evoqu Inc., will ask you to turn on your phone’s GPS or enter your ZIP code and then search for any product. The results you see will indicate online and brick-and-mortar sources, prices, and, in the case of local stores, a map to the nearby locations.

For online sources, you may add the product to a virtual shopping cart, or place a call if the selling website has a telephone option.

With any product on the screen, tap "Advise Me" to see a graph showing a history of the product’s price fluctuations. If you like the product but want to wait to buy, tap "Watch," and set the app to alert you at a future date or when the price moves up or down.

And since few apps now ignore the social aspects of every detail, you can use ShopAdvisor to share what you find via handy links to your text, Twitter, Facebook, or email accounts.

If you’re out at the store and want to compare the prices you find, buy on the fly, or keep a wish list that you can share, get an app such as eBay’s Red Laser or Price Check by Amazon.

Using Price Check, for example, you can scan a bar code, take a photo of the product, or tap the "Say it" icon and speak the product name.

The app returns results for that product from Amazon.com and its large stable of related vendors, from whom you can buy on the spot — right under the nose of the store manager, should you feel so brazen. (This year, Best Buy and Target have said they would match some online prices, under certain conditions.) Sly old Amazon also asks you to "Share (the) in-store price with us." But that’s an option. And, of course, you can notify your social-media contacts with all the particulars.

A crowd-sourcing app, iSlick, is for hunting down and sharing online and off-line freebies and other deals. From a built-in browser, you may simply tap an image or text on a website, then fill in some blanks with your own thoughts on the "Review" screen, and submit that deal for other users of the app, provided by Lanuta.

For off-line deals and sales — like the one I saw for a $3,000 fuel card with purchase of a natural-gas-powered Honda Civic — take a photo and submit information about the deal.

You can browse deals from the "Frontpage" or tap "Categories" to drill down for stuff you are interested in.