The popular HERE maps with offline turn by turn functionality for Windows Phone will no longer be developed by Nokia. Microsoft will take over its future development but that doesn’t mean that Nokia is abandoning HERE maps altogether.
Most recently they had released an Android version as well as an extension for Samsung Gear S smart watch. Nokia still has plans to expand HERE maps and soon they will be announcing an iOS version in 2015. Hopefully Microsoft would be able to maintain HERE maps for Windows Phone with necessary updates in the near future.