Tap the smile icon at the top-right corner, you can see the stickers. Add a sticker you loved to a post, you can resize, scale, and rotate stickers on your post as needed. The layout may be aligned automatically to fit different screens on devices.
There are a plenty of unique stickers on Hearty Journal. The stickers are in different categories including weather, seasons, food, traveling, flower, animals, emoji, slogans, etc.