title: Check whatsapp online status
body: <p>I've been asked to create a mobile application that checks the online status of selected whatsapp contacts, and notifies the user when the selected contact is online. I think this is possible, because it already exists another app that uses the same information and it works at least for someone:</p>
  
  <p><a href="https://play.google.com/store/apps/details?id=com.kiwiio.clonspy" rel="noreferrer">https://play.google.com/store/apps/details?id=com.kiwiio.clonspy</a></p>
  
  <p>However I have no clue about what kind of software interface I should query in order to obtain the whatsapp online status of a contact. </p>
  
  <p>Is there any kind of WhatsApp API that I can use for that purpose? Android or IOs? Or both?</p>