I would like to send the phone position to a web server that could process this info and return the proceced info to the phone by the app.
Could you please give me some tips or examples that I could use to understand how to make this please ?
I need help with the get post method, and what kind of server I need to implement (it would be on a raspberry pi) with some tutorials as example.
Maybe I should begin with sending a position to the server and get a "received et xx:xx" from the server.
It would be more helpful to know what it is you want to eventually achieve, then we can work up the correct framework at the app and the server end. Your raspberry can run all sorts of servers, but I am guessing you will probably use php....
I suggest you POST:
Device / User name / ID | Lat | Lon as a minimum.
Then what do you want to do with this information at the server before you return data?
After with the position info, I would like to get the nearest tourism sites that are included in a database accesible with graphgl requests, use Google distance Matrix api to evaluate distance and propose back to the user a navigation route.
You should be able to do most, if not all, of this using the AI2 Maps and Navigate components, and by creating a feature collection of the tourism sites from your database (where/what is this?). Maps can provide an "as the crow files" distance between two points, Navigate can compute the route between two points, and display this on a map and as a list.