I use Xubuntu 14.04, currently, and it was a HUGE pain trying to get it to recognize my iphone. After scouring the internet for solutions, this is what finally worked for me. At this point, I’m fairly confident I’m not certain what worked exactly, but I followed all of these suggestions, and in order, as I struggled.
1. Make sure you unplug your iphone (or iOS device) from your computer.
2. In a terminal, install:
—————————–
sudo apt-get install libimobiledevice-utils ifuse
sudo apt-get install libimobiledevice-1.2.0
—————————–
3. Now connect your device (iphone, etc.) to your computer.
4. Run this command:
———————–
idevicepair unpair && idevicepair pair
———————–
5. If the operation is successful, you will see “SUCCESSFUL – paired” in the terminal.
6. Disconnect and reconnect your iphone. Click “Trust” when your device asks.
*TIP*
If your iphone is giving the “Unhandled Lockdown Error” message, you need to make sure you plug-in your iphone when it’s not on LockScreen. Make sure to plug-in on the HomeScreen, instead.
After all of this, if the “Unhandled Lockdown Error” is still bothering you, type in terminal:
———————–
sudo chmod 777 /var/lib/lockdown
———————–
If it says folder does not exist, make a folder:
———————–
sudo mkdir /var/lib/lockdown
———————–
.. and try this again:
———————–
sudo chmod 777 /var/lib/lockdown
———————–
Posted by cloudcats 
cLoUDcATs 