Kartasto has a large collection of Finnish maps from open data sources for free, e.g. National Land Survey topographic maps, Traficom sea area maps, Helsinki city maps and several OpenStreetMap variations.
You also get free topographic maps of Sweden, Norway, Denmark, Estonia and Spain.
You can save your favorite places on the map. They are automatically synced between all your devices using iCloud.
Kartasto works wonderfully on both iPhone and iPad, with full keyboard and trackpad support. Future versions will add even more exciting features.
Kartasto Pro unlocks full functionality of the app:
Record workouts using GPS positioning and motion sensors in your iPhone.
Inspect workouts from Health app on your favourite map.
Export recorded workouts and saved places as GPX files.
Import GPX files and view their information on the map.
Download areas of maps to your device for offline use.
New features added in future versions.
If some map available via open data APIs is not yet included, or you want to make your maps available in Kartasto, please email me at firstname.lastname@example.org. Also follow on Twitter at @KartastoApp.