BlueHour
This application suggests a time interval when it is generally the best to take landscape and cityscape photographs. Recommendation is based on your geographic location and local date and time provided by your phone.
There are two special types of natural light (twilight) called blue hour and golden hour. Blue hour occurs before sunrise and after sunset. The sky turns deep blue during this period of time. Golden hour occurs right after sunrise and just before sunset when everything has an orange tint.
