Delta Air Lines introduced bag-tracking on Delta.com in April and now has introduced the service on its Fly Delta Android and iPhone apps.
Once you download the free apps, you can access the Track My Bags feature by entering your bag tag number and last name.
Users of the iPhone app alternately can merely choose to scan the barcode on their luggage receipts to register and get tracking under way, according to the Delta Air Lines blog.
In theory, the tracking can take place from anywhere, even using Wi-Fi on Delta aircraft, the airline says.
The tracking service is designed to inform travelers where their luggage is located and which carousel it should end up on at the airport.
And, of course, if your bag gets lost, you should be able to find out about that out, too.
Here's a Delta video about the new mobile feature.
Delta, of course, is an aggressive proponent of checked bag fees, and its updated apps enable passengers to pay for their bags during mobile check-ins.