WhatsApp will add stickers in the app soon: this is the last news spotted in the iOS version, that shows a new redesign for sending GIFs and, finally, stickers.
As shown here, WhatsApp is going to redesign the GIFs picker, making it very similar to Android and Windows Phone.
Once you start to share GIFs, you can find your recent sent GIFs in the “Recent” tab.
The same will be for Stickers. WhatsApp will use firstly some Facebook Stickers, and you will be able to star your favorite stickers or view your recent ones.