For some people, it’s hard to say thank you to other people, but it makes easy using this app. There are great collection of thank you sticker for you.

How to Use and Install:
-To access iMessage apps, compose a new iMessage to a friend.
-Tap the App Store icon alongside the compose field.
-Tap the lower left corner along with camera to open the app drawer.
- Select your's Stickers app .
- Just with a single tap send stickers.