Ignoring all the other bugs with the chat that should be addressed first…
A fun and useful feature for the chat would be an “open battle request” button, where a player can send out a request for anyone in the alliance to join them in a friendly battle.
Right now we have the chat where we can ask “Anyone for a friendly?” If the chat is working someone can respond, then someone must go out of the chat to their friend’s list to send the request (which is hit or miss at best), or sometimes someone sees such a message and goes to send a request, which the other player won’t see if they are still in the chat tab. There is a pop-up when someone challenges you on any other screen, but not the chat, which seems like it would be the most useful place to have it.
Having a button to request a friendly battle (like requesting dna) would just streamline the process and keep it in one place. It would also make sense if you could battle anyone in your alliance, and not have to go through the process of adding them as a friend first. My friend list and alliance list are pretty much identical at this point.
Again, there are other bugs to fix, but this would be a convenient feature to add once those are sorted out.