The latest version of StreamFX features a choice of image sizes on the My Cam list and the World Cams list.
There is a choice of small and large images. The large image fills the screen of the phone and bleeds of the side edges. Simply scroll left and right to see the whole image.
The small image size fills the screen according to the width of the phone. You can see the difference in effect below. Refresh rate is slightly faster on the small image setting.