I had several points which are important to me.

1 - First I needed a chat that can be seen in mobile (all versions) so I narrowed down the search for html5 chat room that look good on both mobile and pc.
2 - I needed a custom design, I needed my background to be black or transparent. This was very hard to find (my site is dark).
3 - I do not like to install the chat in my server as this is high cpu and resource consumer. So I need a chat service.
4 - Lastly, I needed the ability to add youtube videos and upload images.

I have checked several chats and only 2 met my needs, Chatwing and Newchater

I choose Chatwing finally as it can be integrated into my page and not only as toolbar.