I finally bought my A5it in prospect of making a car audio entertaitement device.
So I browed the forums for the hacks and noticed there are many talks about GPS. Here's what I've been using with my Android Phone when outside my country.
1-I don't need a sophisticated GPS app, just a map helper with my location.
2-No DATA required for roaming is much too expensive.
You can either visualise your trek before hand with a WIFI connection (it keeps the maps visualized in cache) or create an atlas using a third party (see below).
It can use different map source.
On your destop/laptop, you create a custom atlas of the area you need (with the zoom level and shape required), so the size of the data can be limited to save SD space.
Just copy the atlas to the /maverick/tile/ folder with the correct name for the map source (case sensitive) ex : Google Maps must be in /maverick/tile/googlemaps/
I tried maverick on my brand new A5it installed the app way (I saved it using an app saver).
This solution is freeware, mostly opensource (depending on maps provider) and adjustable. Meets all my requirements. So if you don't need a fancy GPS with a soft female voice and 3D visualisation nor streetview but that work DATAless, that's a good way to go.
Hope that helps.