GPS navigation 100% offline (localization mode is "device only")

[AC Question]

Hello,

I am European and I am going to the USA for a few days.
There, I want to lock up any data exchange and connection to the mobile network due to the huge data roaming costs.
Therefore, I want an app providing GPS navigation while being 100% offline (i.e. in flight mode, but with localization enabled in "device only" mode).

I tried a lot of (supposedly) offline GPS navigation apps: Offline Maps & Navigation, Here Maps (by Nokia), Sygic, MapFactor GPS Navigation Maps,...
I indeed have access to the offline maps, but there is no way to get my location: each time the apps say that I have to go to "high accuracy" localization mode to get localization from Google.
This is exactly what I do not want.
I don't care if my localization is less accurate using "device only" pure GPS, I just want it to work.

Can someone tell me which app does this?
Basically, as my phone has a GPS receiver, there should be an app out there that makes my phone work like a TomTom/Garmin offline GPS.
If I have to pay a few € for the app, that's okay.

Thanks in advance for your help.