For most drivers, the safest and smartest choice is to and switch to Magic Earth or OsmAnd. Both allow you to download whole countries to an SD card for offline use, legally, without viruses.
To use iGO Navigation via an SD card, you generally need to download the map data through official channels rather than a direct "free" standalone download, as the software is typically proprietary and linked to specific hardware or licenses. Official Download and Setup Process Igo Navigation Sd Card Free Download
A map pack designed for iGO Primo might not work on iGO 8 or NextGen due to file structure differences ( content folder structures differ). Downloading the wrong version will result in the app crashing or failing to launch. For most drivers, the safest and smartest choice