You have a couple of options...
For starters, you can let your friends know about Socratic by sending them links to the homepage or to the Socratic blog
You can also find Socratic on Twitter
To share individual answers, you can use the Share button located to the top-right of any answer frame.
At that point, you can choose to share the answer on Facebook, Twitter, or Reddit. You can also grab the link to the answer and share it on other online platforms or by way of email.
Simply copy the link and share it!