Many of us don't take advantage of price guarantees after we buy something because it can take a lot of time to monitor this.
But now some apps will do it for you for free.
This could even apply to those deals you thought you were getting for Black Friday, or that are coming up on Cyber Monday.
The first app is called Paribus.
For free, it tracks what you buy online at 30 stores that include Nordstrom, J. Crew and Costco.
You do have to give your email.
Paribus automatically applies for refunds any time a price drops by more than three bucks. Some stores will adjust the price if it drops within ten days of your order. For others it's 30 days.
Unfortunately this won't work for Amazon because it doesn't have a price guarantee.
Also Target and Walmart suspend their usual price guarantees from Thanksgiving to Cyber Monday. The second app Slice works pretty much the same as Paribus.
But here's one big difference:
You'll get the deal if the price drops within seven days. Another difference, Slice doesn't claim the other refunds from stores for you.
It sends you an email that you have to forward to the store to get your refund.
A third app, Earny, is a little different than the other two. It also looks for refunds from your credit card company if they offer a price guarantee.
A lot of them offer that for 30 days after you buy something.
But the downside with this app is it will keep 25 percent of the savings as a fee.