You can use the Secret Background Video Recorder App to record video in the background while using your device for other purposes. It can help you record your favorite moments without having to put your phone in standby mode or turn off the screen. The video will be saved to the specified location and the recordings can be shared with your friends. It can also be used to record important moments. 

The app is very simple to use. Just one click to start recording video/voice in the background. It has no shutter sound, no flash, no preview, and no shutter button. You can record videos for as long as you want and you can also save the recordings to the specified location. It is designed to work with the phone’s built-in microphone.