Most "map" apps are more for exploring where gas/food/etc is so directions can be generated and less about being a useful map.
I find OsmAnd incredible for
- hiking (lots of useful maps, possibility to add overlays like mountain slopes, satellite images, possibility to add maps from other sources as long as you have the tile URL, all maps can be downloaded and used offline, great Altitude/Slope graphs, POI searching),
- cycling (navigation works very well, CyclOSM shows useful information, BRouter for serious bike routing),
- driving (navigation works offline, good as a backup or if you don't like Waze showing you McDonald's ads every time you stop).
Also it's a free software (that you can still pay to help the developers).
(I'd also like the option for bigger / contrastier labels and a way to turn off all the business names because 99% of the time I don't want them cluttering up the map when I'm just flaneuring about London.)
[1] Apple Maps and Google Maps both suffer from this. maps.me also suffers from it but inconsistently - sometimes it'll put it at 50%, sometimes it'll double up at 33% and 66%, sometimes it'll just not label a road...