Help on remote access to ROS-network from Andriod

I am not a star in tunnel protocols (VPN?) but now I have my new nice Samsung (Andriod 4.0.4) tablet and I want to have access to my ROS based network from anywhere in the world.
Behind my network gateway router I have an extended routed network so I want access with my tablet like I am residing on the LAN side of the gateway so I can access any router/client on my network like I am working from it from inside my network.

Can anybody guide me in the setup?
What program needs to be installed on the tablet?
My gateway router is only accessible from the internet by its public IP range. Only one IP is used to grant access to the router.

What to do?

well, just search for VPN client in google play (android market). I am sure there are a lot of softwares to choose from.

@WirelessRudy
Android has built-in L2TP/IPSec client.
This post will guide you with remote access configuration:
http://forum.mikrotik.com/t/solved-l2tp-ipsec-with-android/61619/1
In this thread is also some important info about security:
http://forum.mikrotik.com/t/solved-l2tp-ipsec-with-android/61619/1

HTH,