Daylight has been in my standard collection of weather/environment apps for many years—in fact it’s been the only constant. It’s quicker than the weather apps for the task, and better communicates information about the timing and duration of light, dark, and twilight, which is of general interest but also particularly important for outdoor activities like cycling (do I need a light, and how bright?). Bonus: it also made me aware of civil, nautical, and astronomical standards for twilight.
sharprichnorth about Daylight, v1.6.8