Night mode is an automatic setting which takes advantage of the new wide-angle camera that's in the iPhone 11 and 11 Pro models. It's equipped with a larger sensor that is able to let in more light, allowing for brighter photos when the light is low.
Apple Developing ARM Processors for iPhone
Former P.A. Semi engineer Wei-han Lien lists his current position as "Senior Manager Chip CPU Architect at Apple" in his Linkedin profile. His specialties include high performance microprocessor architecture/micro-architecture and verification. According to his published profile, his present job is managing the "ARM CPU architecture team for iPhone".
Apple presently uses several ARM processors for the existing iPhones but after the company's acquisition of P.A. Semi, Steve Jobs revealed that P.A. Semi would be working on custom chips for iPhones and iPods. Additional speculation pointed to the possibility that Apple had become a major architectural licensee of ARM which would allow them to have more control over the design of the handsets. By developing their own versions of the chips found in the iPhone, Apple could benefit from cost savings and competitive advantages:
By developing its own ARM variant, Apple could create a processor that meets the specific needs of the iPhone and iPod, building support for functions such as the touch screen or scroll wheel into silicon and possibly savings on costs by reducing the number of processors needed in each device. In addition, Apple will be able to maintain tighter controls on who knows what about its future products by disposing of an outside chip supplier.