Bug report:
Steps to reproduce: Send a message to a contact whose Whatsapp is not online. You expect one green tick to show that message has at least reached servers.
Actual outcome: new Yappari does send message correctly, but you only see gray tick which suggests message did not get to Whatsapp servers. If the person's Whatsapp is online, everything works normally.
Workaround: close the chat window and reopen it. This time you do get one green tick.

Anyway, not a big bug