Also a great choice. I prefer organic maps for a variety of reasons (like ability to contribute to the maps), but a lot of people prefer OsmAnd. They are both very good.

OsmAnd is the Swiss army knife of Open Street Map frontends, but as I’m sure you’ll agree on (if you’ve used it), it can be a bit of a headache setting it up, as well as getting familiar with it.

Organic Maps caters more to people seeking a pure alternative to Google/Apple Maps. It’s the layman’s alternative.

If you’re a poweruser, and already familiar with OsmAnd, there’s no point in switching. But in terms of getting other, non tech savvy, people to switch, it’s a great recommendation!

Organic Maps has fewer features and settings, a more stripped-down user interface, and concentrates on what most people use the most (find an address, navigate to it).
It is also much, much faster than OsmAnd.
Personally, I find OsmAnd too slow and clunky, and Organic Maps a bit too basic.
But I prefer Organic Maps 95% of the time.

You might be interested in Magic Earth it is also built on OpenStreetMap but includes crowdsourced traffic data. If you are in a big city then it’s likely they have good data for your area.