Just Downloaded Arc....What do I do with it?

I downloaded ARC thinking it was simply a chrome extension but it obviously is much more than that. I've been caught by how pretty it is...but what can I do with it now? Why should I make the effort to swtich? (I use MAC and am a writer and gamer and mostly consume on Youtube if this helps wiith suggestions)

I want to know from you all why you like it so much and what you use it for. Thanks!