Register for an account at https://www.vpnod.com/account/signup/, you will use the same username and password during registration in your VPN settings. The username is usually an email address
You will receive a confirmation email to verify your email address
Go to Settings button on your iPhone/iPad
Go to General
Add VPN Configuration
Make sure you are on the L2TP tab and enter the following information:
NOTE: Now you will find your VPN on the first page in your Settings and it is controllable directly from there.