There is always the moment you just need to spy on someone to make sure he or she is saying what he or she is claiming, while back in the day in order to become a spy you needed intense training, professional equipment and some gadgets from Q butOf course this is the 21st century and spying on a friend is now much easier, specially if you want to do it using Whatsapp.
Spy on your Whatsapp contacts using WhatsDog
Using an app called WhatsDog (the App is only available on Android) you can view your friends activity by day of the week, the times he or she has been connected or disconnected, shows the level of WhatsApp usage and you can even enable notifications for certain contacts so you know when he or she has been using or reading their whatsapp messages.
The app can even be used when you have been blocked by a user and that someone wouldn’t know you are spying on them. You can download the app here