Quick shoutout for Trail Sense for Android. Designed to function offline, lots of cool navigation/basic tools I haven't used outside of the GPS and compass, reasonable permissions, etc. One of those "You don't know how useful it is until you don't have connectivity" things.
google also allows offline caching, but also needs to be set up ahead of time. AFAIK once you set a region to download, it will update that cache regularly.
I would expect this is a feature that most map apps would offer