How can I directly, wirelessly copy files between Galaxy S3 and Ubuntu? I would like to copy files between Galaxy S3 and Ubuntu


without giving away too many privileges - just copying said file
without any rooty system modifications (I want to keep the carrier-warranty including their system updates - currently 4.1.2; and I want to show this to hapless users too - without them calling me back...)
without using an USB cable (I know how to do this like in this answer, that is, connecting as a camera ; but this gives one complete rw access in some directories) 
preferably without any extra apps to install.


It seems there are two options left (when going through the list offered by the "Share via" button): either Bluetooth or Wi-Fi.

For Bluetooth such a transfer worked with an out-of-the-box preinstalled Windows. So it is not the Android as such which is a problem, rather Ubuntu but there was no answer nor interest on AU.

When I try to send it via Bluetooth I just get the notification: "Bluetooth share: Sent 0 successful, 1 failed". However, I can transfer files from Ubuntu to Android.

So how can I copy files successfully?
There are multiple possibilities to do so. If the opposite direction is OK with you (i.e. initiating the transfer from your Ubuntu machine), you might want to take a look at apps like WebSharing or Samba Server, which require little permissions. AirDroid is quite famous, but you probably won't like its permission requests (with that app you can maintain almost all your device).

Initiating transfers from your Android device, some file managers might be interesting. So e.g. ES File Explorer File Manager (which I use myself). This app can even auto-discover your Samba resources, so you can directly copy files in both directions.

All mentioned solutions work via WiFi and require both ends (Android and Ubuntu) being members of the same network.