VeriFly is available only on iOS devices for now. Denver passengers can reserve a 15-minute window to pass through designated TSA airport security lanes up to two weeks in advance. On travel day, passengers are asked to fill out a health questionnaire and complete a temperature check before arriving at the airport. Once at the airport, passengers are directed to a separate VeriFly checkpoint that uses touchless electronic entry gates that lead to Transportation Security Administration lines for both standard and TSA PreCheck-approved travelers. Mobile QR codes allow entry to gate trains, which are limited to 12 people per car.

Denver International Airport spokesperson Alex Renteria confirmed to The Washington Post that this program is not a TSA administered program.

“To ensure that the security lanes and dedicated train car are not overwhelmed, we are limiting reservations each hour,” Denver International’s VeriFly guidance stated. “Additionally, we plan accordingly around peak times so we can space passengers out and avoid overcrowding.”

The Denver airport is calling on passengers to help test out the pilot program, saying on Twitter that the reservations system and app are “for folks who might be high risk or want a little more confidence as they move through security and to their gate.” It also notes in a tweet that the optional program is not intended to replace standard security processes in the future.