New York City Night & Day Free is a personalization wallpaper app developed by apps on air for Android devices. With this app, you can give your device a cosmopolitan look by carrying the skyline of one of the world's great cities on your home screen. The wallpaper switches between day and night modes depending on the local sunrise and sunset times.

The wallpaper is available in 4K resolution (4096x2048), ensuring perfect image quality on all devices in portrait and landscape mode. It features static, auto-move, and gyro motion modes, along with daydream mode support. The app is also compatible with Android watches and has sunrise/sunset based on actual position or time of New York City. Additionally, you can manually set the time of sunrise/sunset.

It is worth noting that the app uses the GPS fine permission to calculate the exact time of sunset and sunrise. However, to avoid high power consumption, the app does not turn on GPS, but instead uses the last known position.

Overall, New York City Night & Day Free is an excellent wallpaper app for those who want to add a cosmopolitan touch to their Android device. The app is user-friendly and offers a variety of features that allow customization to your preference.