I think Whatsapp on IPOD can only be installed on a jailbroken Device coz an IPod doesnt support Whatsapp. So Before ypu go any further i suggest you get anIphonecasue its the only I Device that supports Whatsapp. In case you want to continue i am not responsible for Whatwever happens to your Ipod.....
1. First you have to Jailbreak yo iPod touch.
Step 1: Download and install iPhone Configuration Utility for Windows.(Google Download links)
Step 2: From iTunes, search for "WhatsApp Messenger"and download it.
Step 3: Launch iPhone Configuration Utility, which you should have installed earlier. From the hand-hand side, select your iPod touch and navigate over to the "Applications" tab.
Step 4: Click on "Add IPA" and navigate select the WhatsApp file you downloaded earlier, which should be placed under iTunes Media > Mobile Applications. Alternatively, you can drag the WhatsApp file from iTunes to your desktop, then point iPhone Configuration Utility there.
Step 5: Once the right IPA is selected, simply scroll down and hit "Install". In a matter of seconds, WhatsApp should be installed on your iPod touch.
2- Making Whatsapp Compatible.
Now simply launch Cydia from your iPod touch and look up "WhatsPad". Install the first result, which should be from the BigBoss repository and its free. Simply reboot your iPod touch after the install.
You’re done! You can now launch WhatsApp, which will work the way it works on the iPhone except that you’ll need a Wi-Fi connection all the time. Remember you’ll need to enter a 3-digit activation PIN, therefore keep in mind that since it’s a one time process, so you would need a cellphone with text message receiving capabilities. Just input the phone number in WhatsApp on your iPod touch, and the 3-digit PIN will be sent to you.
If you face any problems you can Private message me ill send you a video.