International travelers arriving at Chicago’s O’Hare airport should find shorter lines at passport control thanks to a smartphone app.

The free Mobile Passport Control app was developed for U.S. Customs and Border Protection. It allows travelers to plug in their passport information and submit customs declaration forms before arrival.

They can then get in a designated line at passport control and show the customs officer a bar-coded receipt on their phone or tablet.

Airports in Atlanta, Miami and Seattle are also using the system, which will be expanded to 20 airports altogether.

Android and iPhone users can download the app from the Google Play Store or the Apple App Store.

International passenger traffic increased by nearly 5 percent last year at O’Hare to about 10.8 million people.

(AP)