I think hughes's point was why isn't this just a website? (Which would work on all platforms, including iOS and desktop PCs, and would be searchable through Google.)
Maybe because of connectivity? Not everyone has a data plan when they arrive to the country.
Offline-capable websites are a thing. Plus you still need a connection to download the app initially anyway.
We want users to peruse the knowledge bank offline due to the cost of data and the potential that a detained or soon-to-be-detained immigrant may not have an internet connection.