Navione is rarely sold as a standalone app on the Google Play Store. Instead, it exists in a "gray market" of hardware-software bundles.
Most NaviOne systems come pre-installed on an SD card or internal storage. If you are installing it yourself: Locate the APK/EXE : For Android units, find the navione gps software exclusive
Looking at the results, result 0 is "langflow/.devcontainer/Navione GPS Software Download Benefits Features and Compatibility.md", which seems to be about "Navione GPS Software". Result 1 mentions "NAVONE 3000". There are also many results for "Navion" and "Navigon". It's likely the user intends "Navione" or perhaps "Navion" or "Navigon". I need to explore further. Navione is rarely sold as a standalone app