The fact that start and endpoints of calculated routes are uploaded to a server (and until recently unencrypted[1]) doesn't inspire confidence. The app also collects analytic statistics and serves ads by default. If you're interested in a maps application that is not "trying to track you everywhere", OsmAnd[2] is a better choice.

Also, Maps.me is owned by mail.ru which has a similar business model to Google with arguably more lax security practices.

[1]https://github.com/mapsme/omim/issues/1073 [2]http://osmand.net