Is it possible to toggle end user's camera from the end of the caller?

Hello Jitsi guys,
I have some questions on free API of jisti.

  1. Is it possible if the camera can be toggled from the end of the caller?
  2. Can we customize the buttons that show up during the call?
  3. Also can we lock the screen bar in place on the mobile side during the call so it doesn’t disappear during call time?
  4. When i make call using mobile browsers, call screen is not fit like original jitsi view. Is it possible to make mobile view of call screen?

Thanks in advance if anyone help me