LSReplaceCam allows you to replace the camera page on the lock screen with any app of your choosing. Simply go into Settings > LSReplaceCam, tap on your desired app, and it will automatically respring. From then on, swiping to the camera page or 3D Touching the camera button on iPhone X will instead open the specified app.
I would also like to give credit to iMokhles, who created LSAppChanger, as their source code allowed me to quickly discover SBApplicationController's cameraApplication method. Without them, this probably would have taken a lot longer.
To make it clear, it resprings as soon as you select an app from settings