Well I found something good on my own. Tried over 20 of them on the way.
After I tested like 20 of them I realized that none is as good as Rumbletalk is.
Why I like Rumbletalk? I can upload youtube videos, charts, works nice on phones, it is not a resourse hog and it is a safe application unlike many others chat application out there. You can also manage the design just as much as you want.
It really is the best embed chat room
application as I heard many times on the internet.