Samsung Galaxy and many Android phones have a manual "Pro" mode that's perfect for the Northern Lights. A few settings and a steady hold are all you need.
Use Pro / Night mode
Open the camera's Pro mode (or Night mode). Set shutter to 8–15 seconds, ISO around 800–1600, and focus to manual infinity.
Steady and shoot
Mount the phone on a tripod or rest it on something solid, then use the timer so your tap doesn't cause shake. Shoot RAW if your phone offers it.
Adjust to the display
For a faint aurora, use a longer shutter (15–25s); for a fast, active display, shorten it (4–8s) so the curtains don't blur. Lower ISO if shots look grainy.
Battery in the cold
Keep the phone in an inner pocket between shots — Arctic cold drains batteries fast. A guide on a photography tour helps you dial it in.