Facebook-owned WhatsApp is working on new, animated stickers, which would be active within the chat window, and active as you scroll.
As reported by Android Police:
"The feature showed up in beta v126.96.36.199 and then disappeared in v188.8.131.52. When it's working, stickers from animated packs are live in the conversation, though they only animate once and stop. You need to scroll up or down to trigger them to play again."
Android Police notes that the functionality of the stickers may not be complete yet, but it seems that this is how they will appear, and respond, in your WhatsApp chat streams.
It would add another element to your WhatsApp sharing options. Thus far, WhatsApp has only enabled users to add regular, static stickers in chats, while the overall functionality of WhatsApp has been largely limited to text chats. The app does have its own Stories like tool, however, and Facebook has been exploring more ways to incorporate more functionality. Animated stickers would be a small element in this respect - but still, it's another step forward for WhatsApp.
And it may be another small step forward in Facebook's broader plans for full integration of its messaging apps.
In theory, if Facebook is to fully incorporate the messaging functionalities of Messenger, Instagram and WhatsApp, then each platform will need to support the same tools, in order to ensure that users can share the same across the three.
And sure enough, the exact same animated sticker pack in the above example is also available in Messenger.
So it likely is part of that broader messaging integration - which also means that you'll probably soon have a heap more animated sticker options in Instagram Direct as well.
We'll keep you updated on any progress.