Mobile Passport App was a free alternative to Global Entry that works at 25 airports. They have now added a premium version of the app that costs $14.99 per year, there is a free 7 day trial. The premium features are really just features that used to be free, for example you’ll now need premium to store your passport details and to use the document scanner. This means if you want to use the free app you’ll need to manually enter your passport details each time.
Most readers of this site will thankfully have Global Entry from one of the many credit cards that offer this feature, but this is incredibly annoying for those without access. As long as you don’t update to the latest version of the app you should be able to continue to store your passport information in the app, but I’m sure at some stage they will force an upgrade or the app won’t work.
Hat tip to reader BTD & Rapid Travel Chai
