You will need to have used iPod Touch Jailbreak software to allow for you to install applications. After you have done that you can use this tutorial to add applications.
– Download SFTP
– Log into you iPod Touch using SFTP:
IP Address: Find your iPod Touch Wifi Ip Address (settings>wifi>blue arrow on what wifi network you are using and it will be there)
User: root, Password: alpine.
If you would like to find out how to install the default apps that are on the iPhone check out this tutorial.