For this you need of course a phone that allows you to use the camera manually and set the exposure also manually. Usually, the latest generation phones allow this if they work with camera2 api. There are several applications if your camera does not have the manual mode that lets you force the phone to use the camera2 if it exists in it. I'm honest for the beginning I suggest OpenCamera which is a free app or FV-5 camera that is paid but you can test light version. If your phone is compatible then you will be able to make stunning photos at night but the phone will have to stay still for as long as the picture takes. My phone can take a picture for up to 10 seconds but newer phones allow up to 30 seconds for a photo that means all the light entering in the camera will create a picture and the objects that are moving appear erased or not at all. In order to make sharp photos tou will need a tripod. Here you have a picture with 10 second exposure that was made at night from me in the night using my S7 edge, you can see the stars in the background. I hope you enjoyed this little tutorial and hope to get fabulous pictures. Success!