If we can select photos from gallery to apply rain effects in different angles like right, left, top.
Rain falls drop in different side like:
Once finish to apply a rain effect go through the set wallpaper option.
It can show more function like pic sound effect when rain fall drop on screen.
If we don't want to apply sound effects you can mute it on setting option.
Preview the rain fall effects at setting wallpaper section.
Then set wallpaper.
We can share rain fall photos on social networks etc.