If you need a community trading chat (social trading) you can use whatsup, but it is not convenient using a small screen.
I suggest you add trading chat room to your website, it works much better with graphs, it is more easy to see the graphs in a pc than a phone.
I am using Interactive brokers for years. They are good. They have also API where you can automate your buy/sell command from an external software/excel.
I made a lot of research in finding a chatroom for my Algo-Trading website. I used envolve for a while till they closed up, pitty. I tried IRC but I truly did not like the look and feel and the "mess" of text in there.
I had several points which are important to me.
1 - First I needed a chat...