Please see below:
1. To use share button
On your sound screen, there is " < " shaped share button.
Tap the share button and you will see below:
Share on Facebook: Tap this and share sound on Facebook
Share on Twitter: Tap this and share sound on Twitter
Copy sound URL: This is the URL to listen your sound on web player
Copy nana link: This is the URL to share your sound within nana
2. To share sound on your Twitter/Facebook automatically
On the next page of "effect" screen after recording your sound, you see Twitter/Facebook button on the button.
These are auto-share button to share on Twitter/Facebook.
If it's on, every time you record, your sound will be posted on Twitter/Facebook.