mahlernim/google-timeline-visualizer ? reverse-engineered prompt

Build me an app that turns a Google Timeline export into a shareable travel video.

I want to load a Timeline.json file, pick a date range or exact trip dates, preview the animated map, and then generate an MP4 that shows my journey with a moving marker and a nice zoomed out ending view. The app should keep a list of the videos I’ve made, let me play or share them later, and make it easy to add older MP4s too.

Please include a simple settings area for things like camera movement, video size, and other defaults, plus a way to change the app language. It should work on Android, and if it makes sense, also have a browser version that works on iPhone without uploading my data anywhere. Keep the flow simple and friendly, with clear instructions for getting the Timeline file and creating the video. If you need to check anything up to date, look at the current docs online.