This texture pack changes stained glass's appearance to mimic the style and movement of the world border's texture.
Border Glass, it's mesmerizing!: 
Come with panes too:
Available in 16 fun colors:
Available for 1.12.2 & 1.16.4. You can use it in 1.17 snapshots too, though the game will say it's incompatible.
The Paint's Border Glass Team
