The idea is a good one. But like it says, the app as well as a couple of others were made for other countries and not the U.S.For instance I no longer travel, and I am a U. S. Citizen, have been since birth. While when traveling to and through other countries one needs to carry a passport, while in the U.S. I do not have to carry a passport. My passport expired about 10 years ago, and I have not felt it necessary to renew because like I said, I no longer at my age, travel so I don’t need one. However, when trying to create an account with this app, they ask or my passport number, if not given, you cannot complete the registration. Therefore, this app is useless to people like me. Too bad, the idea is a good one and certainly a useful one.If you ever create an app that can be used everywhere, please let me know. I would like to have it. Thank you. Trisha