1. Click a contact in the Chats column, or Message on someone's profile.
2. Type in the box at the bottom of the window and press Enter to send. Shift + Enter starts a new line.

You'll see Seen under your last message when the other person has read it, and is typing… while they reply.

If a notice says the person has not opened the new chat yet, they will be able to read the messages you send after their next visit to Wiply.