tl;dr: Frustrated that a travel agency required installing a 43MB Android app just to view an itinerary (which was really just HTML, images, and PDFs with added tracking and ads), the author reverse-engineered it by rooting an Android emulator and intercepting traffic with HTTP Toolkit. They discovered the app fetches JSON from an API using concatenated username-password credentials in the URL, then wrote a Ruby script to convert that JSON into a lightweight, password-protected webpage for their tour group—stripping ads and tracking while gaining bookmarking, printing, and accessibility benefits.