How to create animated background gradient like Instagram app?
<p>Below are screenshots of instagram app. The background keeps on transforming from one gradient to other very beautifully. 
<a href="https://i.stack.imgur.com/4d7GU.png" rel="noreferrer"><img src="https://i.stack.imgur.com/4d7GU.png" alt="Instagram background gradient"></a></p>

<p><a href="https://i.stack.imgur.com/0ZaNS.png" rel="noreferrer"><img src="https://i.stack.imgur.com/0ZaNS.png" alt="Instagram background gradient"></a></p>

<p>I want to know how can I achieve this. IS THERE ANY CODE TO ANIMATE A GRADIENT AUTOMATICALLY OR DO I NEED TO ADD DIFFERENT GRADIENTS WITH SLIGHT VARIATION, and if  I use it won't cause any copyright issues with Instagram? I have tried animating using multiple gradient files with slight variation using Frame Animation but it isn't smooth and doesn't work well. Thanks</p>