Track whatsapp message from another device?

Recently I came across this question in a forum

Can I track whatsapp messages from another device? Say from my PC to an iPhone?

I was also wondering that is there a way to do this, and I found this

mSPY is a spying app which when installed in someone’s phone allows you to track it and they whatsapp message from your PC or iPhone without even touching his phone and without letting them know.

mSPY once installed, hides itself and upload all its content online which you can view by logging in to your mSPY account. Other than whatsapp message with mSPY you can spy on their text msg, calls, and even their location.

mSPY is a paid app which you can download by clicking the banner below.