How to establish a connection with Fritz Box VPN from Windows 7 without any special client tools?
Some people means that Fritz Box uses IPSec with ESP mode...
closed as off-topic by Dennis Kaarsemaker, Nathan C, kce, Ward, Dave M Jul 7 '13 at 15:43
This question appears to be off-topic. The users who voted to close gave this specific reason:
There are instructions available how to connect to the VPN with different OSes (obviously without the FritzApp). You could try to adept the instructions for Android found here.
It should not make any difference if the client is actually an Android device or a windows machine.