Hi! Have you ever heard of reactJS? It's a JavaScript library for building user interfaces. 
No, I don't know much about programming. When was it invented?
It was first deployed on Facebook's news feed in 2011. 
Can it be used on iPhone or Android?
Yes. But it is called React Native. It enables native Android and iOS development with React. 
What are some of it's features?
It allows developers to create large web-applications that use data and can change over time without reloading the page. Like FB's newsfeed. 
Is it used in other applications that we use daily like Facebook?
Yes, instagram and a community of of individual developers and corporations.