Open Camera has the following features:
* Option to auto-level so your pictures are perfectly level no matter what.
* Expose your camera's functionality: support for scene modes, color effects, white balance, ISO, exposure compensation/lock, selfie with "screen flash", HD video and more.
* Handy remote controls: timer (with optional voice countdown), auto-repeat mode (with configurable delay), Bluetooth LE remote control (for specifically supported smartphone housing).
* Option to take photo remotely by making a noise.
* Configurable volume keys and user interface.
* Upside-down preview option for use with attachable lenses.
* Overlay a choice of grids and crop guides.
* Optional GPS location tagging (geotagging) of photos and videos; for photos this includes compass direction (GPSImgDirection, GPSImgDirectionRef).
* Apply date and timestamp, location coordinates, and custom text to photos; store date/time and location as video subtitles (.SRT).
* Option to remove device exif metadata from photos.
* Panorama, including for front camera.
* Support for HDR (with auto-alignment and ghost removal) and Exposure Bracketing.
* Support for Camera2 API: manual controls (with optional focus assist); burst mode; RAW (DNG) files; camera vendor extensions; slow motion video; log profile video.
* Noise reduction (including low light night mode) and Dynamic range optimisation modes.
* Options for on-screen histogram, zebra stripes, focus peaking.
* Focus bracketing mode.
* No third party ads in the app (I only run third party ads on the website). Open Source.

(Some features may not be available on all devices, as they may depend on hardware or camera features, the Android version, etc.)

Website (and links to source code): http://opencamera.org.uk/

Note that it's not possible for me to test Open Camera on every Android device out there, so please test before using Open Camera to photo/video your wedding etc :)

App icon by Adam Lapinski. Open Camera also uses content under third party licences, see https://opencamera.org.uk/#licence