Allowing the the session name/number to be submitted with the Enter key on the keyboard would be a simple change that would make the end user experience that much easier. Right now, the right arrow icon (which is quite subtle) must be clicked. Most users have the expectation that pressing enter will submit whatever they've typed in, so there may be some occasions where users have pressed the Enter key and are oblivious to the fact that nothing is happening and they must click the arrow.
Perhaps even better than this would be for the code to submitted automatically as long as it's a valid code. Visual feedback should be displayed to the user so they know that they don't need to press anything, such as a spinner and disabled text field.
Customer support service by UserEcho