Yanwa
Spy tracker For WhatsApp, Telegram, VK
Push notifications
When a profile enters the network, Yanwa sends a push
History of time intervals
Agent lets you keep track time of profiles
Summary of the last seen
Short summary

Sniffer gives you the ability to add WhatsApp and VK pages for which statistics are needed. Plus, it's getting push notifications about online and offline. No need to be a hacker to use the app. It's not hack tool