Camera One is an app that allows users to control their phone cameras through their Galaxy Watch or Android Wear OS smartwatches. The app has a variety of use cases, including taking selfies or group photos, viewing and recording video, listening and recording audio, viewing hard-to-reach places, using it as a security system, and as a baby monitor. The app has a range of features, including the ability to switch between rear and front cameras, take photos or videos by turning the wrist, listen to phone sound, and use various camera settings such as zoom, flash, exposure, and filters.

The app also has a time-lapse video feature, with options for x4, x8, x16, and x32, as well as a timer with options for 2, 5, and 10 seconds. Users can save copies of photos on their watch and save files on the SD card. The app works even when the phone screen is off, and all settings are available on the smartwatch.

To change camera settings, users can tap on the top of the screen where it says "Zoom: x1.0" and rotate the bezel to select the desired value. For watches without a bezel, users can swipe left or right on any screen area. The app also has a sound toggle, and users can switch between self-timer and voice recorder by long-tapping the sound toggle button. Audio files are saved in Phone storage \ Voice Recorder.

If users experience high battery consumption, they should close the app using the "Back" button instead of the "Home" button. If there are connection issues, users can tap "Settings / Permissions" inside the Camera One app on their phone and follow the instructions. The app is compatible with a range of Samsung and Wear OS smartwatches. Users can try the premium version for free during the trial period and buy it later if they are satisfied with the functionality.