Knock. The ultimate nonverbal communication.
Knock is the most primitive, but innovative way of communication.
Once you tap your friend’s door, your friend will notice you.
You don’t have to think what to write or say. You don’t even need a letter to communicate with your friend.
The only two features:
Knock – Send a notice to your friend. Knock back to your friend.
Search – Find your friend with a user name.
We always welcome your wish.
Tell us anytime what you want for, or what you think of this app.