WhatsApp end-to-end encryption Earlier this week, I saw below message on WhatsApp

 (Click for larger Variant) 



What does this means to the User?


  With end-to-end encryption, messages are scrambled as they leave the
  sender's device and can only be decrypted by the recipient's device.
  It renders messages unreadable if they are intercepted, for example by
  criminals.


My question is: Does this end-to-end encryption applies to individual chat and to group chat between Android-only devices or it also works on other platforms, Since WhatsApp is available on iOS, Windows Mobile also.
It appears to be between all platforms, as its written here:

https://whispersystems.org/blog/whatsapp-complete/

"Over the past year, we've been progressively rolling out Signal Protocol support for all WhatsApp communication across all WhatsApp clients. This includes chats, group chats, attachments, voice notes, and voice calls across Android, iPhone, Windows Phone, Nokia S40, Nokia S60, Blackberry, and BB10."