Ok, regardless that you should use a better camera, you can do Ok with your phone.
Take it off of auto and put it on manual by hitting the auto tab, then the letter M.
Set the iso to 800, and then set the shutter speed to the bottom or 4.
that will be a 4 second exposure. Leave it on that, but keep your hands ultra steady or mount the phone to a tri pod.
If it looks too bright, change it to iso 400.
But you want a timed exposure, so leave it on 4 seconds if you want nice trails.
Posted via Android Central App using the all new HTC One (m8)