Shutter Speed Tutorial - Luwian iPhone Academy of Photography
You can change the shutter speed on your camera to any value between 0 and 1 second. As you adjust it, you can see the changes on the Camera Status Bar.
Note that the maximum shutter speed setting for an iPhone is currently limited to 1 second. Use Luwian Neutral-density mode if you need to take photographs with a shutter speed longer than one second.
When you select the shutter speed, the ISO will also be manual. Shutter speed control is useful when you want a higher quality image, control over ISO, and long exposure at night or in a low-light environment.