Disclaimer: The app is closed source, so all we can go off is the developer’s word, although the fact the government removed it is a strong indicator they don’t have access to data from the app

The developer stated they do not even retain any identifying data, so the only data the government could get is public anyway. Through Apple they’d be able to see who downloaded it, and likely when it was used. Your defense would be easy enough though: “I just wanted to make sure the libs weren’t harassing our fascist patriotic ICE agents near me”