Its made by Pavel Dobryakov (not me!) in unity. With his special shaders and the ability to set it as a live wallpaper its a must for any android user out there.
It comes with many toggles to change the way the fluids look and behave.
It comes with a free version and a paid one, with the only difference being the amount of options.
If there are any bugs or questions please join the discord: https://discord.gg/yDnsFw7 and don't ask them here! I'm not the developer of this app so I cant help with any of them!