Long exposure

1. Mount the phone on a tripod and set the self-timer to 2 seconds.
2. Switch exposure to manual mode and set a low ISO.
3. Lengthen the shutter speed with the button or with the wheel in SS mode. The longest shutter speed is set by the phone's camera.
4. Turn on manual focus, magnify the area you need with a double tap and focus on it. In the dark, autofocus often misses.

At shutter speeds of one second or longer, the ring around the shutter button shows the time remaining, and the viewfinder is covered by the shutter curtains.