There is nothing new using and creating custom stickers in mobile chat applications. The latest and greatest addition to the family of such applications and development platform was done by Apple few days ago. After their massive release of iOS 10, the iMessage, at last, got its own stickers (that are applications themselves).
In a matter of a day I was contacted by team behind Stickers.Place collaboration. Guys invited talented illustrators to create stickers packs for iMessage and created a platform where any illustrator can join, create and share the best emotional stickers with audience.