The NavFree app includes a map and maybe an address database. That means it works offline as well as when you have an internet connection. The lighter Map apps will only work if you have an internet connection, at least when you are setting up the trip. Most of them will work offline after the trip is computed.
You won't find a full offline GPS navigation app much smaller than NavFree. It's the nature of the beast.
There are lots of GPS navigation apps of various types. Many are free, or provide limited light versions. It depends on what you want to do with them, so if you were a bit more specific about what you want the app for, you might get more recommendations.
However, as far as I know, NavFree is the only free car navigation app with full offline maps. Some versions may still require internet for address lookup. The USA version does not, but it's unclear whether this recent update applies to all regions.