Update: This now has a GUI, check it out here.
This worked for iOS 8.3 device:
1) According to this it needs new ifuse install that matches libimobiledevide. According to this the --documents command was added in 1.1.3 and the version in Ubuntu is 1.1.2. So, I downloaded the ifuse-1.1.3.tar.bz2 from the site.
2) Install fuse library or configure will complain:
sudo apt-get install libfuse-dev build-essential
./configure in the unzipped folder, then
make install as described in the readme file.
4) Verify it upgraded by running
ifuse --version (1.1.3)
5) Add yourself to fuse users:
sudo modprobe fuse
sudo adduser $USER fuse
and log out, log back in.
---- (The GUI linked above will run the steps below, much easier) ----
6) Create a folder to mount an app's documents, say,
7) To connect to the VLC app for example, run
ifuse --documents org.videolan.vlc-ios /tmp/vlctest/
8) When done, unmount with
fusermount -u /tmp/vlctest
Unfortunately the ideviceinstaller isn't compiling for me, even with
libzip-dev installed. It apparently hasn't been updated for recent libimobiledevice in a loong time.