Which here like map app?
 

Is there a map/gps planning app capable of downloading map data offline for offline use, as in offline route planning? something like the here app for ios/android but for linux?

:twocents:

https://www.gpsbabel.org/

My samsung has a Verizon contract and it guides me on the handle bars of my motorcycle by voice commands/ear buds using google maps. Also. " I Go My Way " is available on my phone.

So offline is not needed by me. But the above link I gave you handles offline.

Also you can check out

https://sourceforge.net/projects/mobac/

Then there is

https://github.com/heldersepu/GMapCatcher

info:

https://code.google.com/archive/p/gmapcatcher/

^ gmapcatcher is in the AUR and got 18 votes; that's the one i would try first (but searching my software repos for "offline maps" gave more results).

on my phone, i have OSMAnd installed. tricky to use, but invaluable when you don't have internet (and need a map).