Bringing your subject into and out of focus can produce a dynamic shot that makes your broadcast and recording look extremely professional. You can adjust the Depth-Of-Field on a shot using the "Focus" slider.
To start adjusting the focus and depth of field, tap on the Camera Control icon in the lower right to bring up the camera control menu.
Make sure the camera source you want to adjust is in the live window, or the preview window if it is enabled.
Now, next to Focus tap on the "M" to change the setting from auto to manual. You will see a slider appear on the video. Sliding that will pull the focus in and out.
If you are using an iPhone with the horizontal UI, the process is very similar.
The camera control icon is in the lower left, tap on it there.
You can scroll across to find the option that you need.