Pssst. Mobile Passport is the best-kept secret in air travel - The Washington Post

After a long-haul flight home from abroad, it is soul-crushing to see a long, snaking line to get through customs when you land at an American airport. If you’re lucky, maybe it moves quickly. If you’re smart, you have Mobile Passport downloaded on your phone.
https://www.washingtonpost.com/travel/tips/pssst-mobile-passport-is-best-kept-secret-air-travel/