A women's clothing and accessories application called Poshmark for the iPhone and iPad matches sellers with buyers.
Sellers use the free app to snap photos of their items, upload them to their mobile device, then list them for sale.
Sellers set their own price, typically from about 20 to 80 percent off retail.
Unlike eBay, there's no bidding and the listing can remain for sale indefinitely.
Once an item sells, Poshmark pays for all shipping costs. The company pockets a flat 20 percent of the sales price.
Poshmark's founder says if buyers have a problem with the items, the company offers a guarantee: "If within three days you find a problem, see an issue, you let us know, and your entire money will be refunded back to you," says Manish Chandra, the chief executive officer of Poshmark.
There are other shopping apps that work with both the iPhone, iPad and Android.
Etsy lists handmade and vintage items.
EggDrop matches local buyers and sellers, similar to Craigslist.
Zaarly is an app that allows you to post what you want and how much you'd like to pay for it, then receive bids from other users.
Of course, for avid shoppers, bargain-shopping apps only work if the shopper doesn't go too overboard.
Poshmark only works right now with the iPhone and iPad.