U.S. citizens and Canadian visitors are allowed to use the Mobile Passport app authorized by U.S. Customs and Border Protection to expedite their entry process into the United States. By submitting the passport information and the customs declaration via the app upon landing, travelers will reduce their inspection time and overall wait times.

The app is for free and can be downloaded from the Google Play Store and Apple App Store.

Please refer to the website of U.S. Customs and Border Protection (CBP) for more information.
https://www.cbp.gov/travel/us-citizens/mobile-passport-control