How to check the VPN setting created by an app on an iOS device?
Yes you can on a jailbroken iPhone using an app called OpenSSH.

It will allow you access to all the system files and in normally conditions you can simple change the extension to .txt and open it with textedit for example.

What you’ll need:


A jailbroken iPhone/iPod Touch with Cydia installed.
OpenSSH Cydia Package.
Wi-Fi and Internet access on the device.
Mac/PC on the same Wi-Fi connection
Suitable FTP/SSH clients like Cyberduck, Transmit etc.


Here is the guide on CultofMac

Also a link to the OpenSSH Cydia Package

Basic Instructions:


install the OpenSSH package


(click, Install, Confirm, Close, Back)

open Wi-Fi from Settings
click your network's 
read the "IP Address" field


(example: 192.168.1.100)

open Terminal on desktop


(open Spotlight, search for "Terminal")
Or if you're on Windows, you can use a desktop terminal application such as PuTTY(http://www.putty.org/).

run "ssh root@[insert IP Address]"


(example: ssh root@192.168.1.100)

wait a few minutes (just once)


(it's generating some crypto keys)

accept new computer host key


(if it doesn't ask you, that's fine)

log in with password "alpine"


(you should change this now)