Open Camera is an Open Source Camera app for Android phones and tablets. Features:
Option to auto-stabilise so your pictures are perfectly level no matter what.
Expose your camera's functionality: support for focus modes, scene modes, color effects, white balance, ISO, exposure compensation/lock, face detection, torch.
Video recording (supports all available resolutions including HD).
Handy remote controls: timer (with optional voice countdown), auto-repeat mode (with configurable delay).
Option to take photo remotely by making a noise (e.g., voice, whistle), or by voice command "cheese".
Configurable volume keys.
Optimise GUI for left or right-handed users.
Zoom via multi-touch gesture and single-touch control.
Ability to lock orientation to portrait or landscape for photo or video.
Choice of save folder (including support for Lollipop's Storage Access Framework).
Disable shutter sound.
Overlay a choice of grids (including "rule of thirds") and crop guides.
Optional GPS location tagging (geotagging) of photos and videos; for photos this includes compass direction (GPSImgDirection, GPSImgDirectionRef).
Apply a date and timestamp, location coordinates, and custom text to photos; store date/time and location as video subtitles (.SRT).
Yes you can take a selfie (also known as front camera), includes support for "screen flash".
Support for (some) external microphones.
Widget to automatically take a photo after launching.
Support for Android 5 Camera2 API: manual focus distance; manual ISO; manual exposure time; RAW (DNG) files.
Support for HDR and Exposure Bracketing (Camera2 only).
Dynamic range optimisation mode for better quality photos.
Small file size.
Completely free, and no ads in the app. Open Source.
Comments and Reviews
Since I installed LineageOS on my OnePlus One, my main complaint was that the default camera app that comes with the installation is just unusable. It would take about 5-7 seconds to open, and when I tried to take a picture, it would take two pictures; one that is horribly over-exposed, and the other is too dark to see hardly anything.
I was able to find Open Camera on F-Droid and set it as my default camera app, and it opens in less than a second and takes clear and perfect pictures with every click!
On a Pixel phone it gives the same image quality as the Pixel Camera. It also seems less overly-processed than Pixel Camera.
It is crazy, I installed it in my samsung galaxy a34 5G. and you can literally modify all the garlics, either, iso, the focus, you have even a lot of grids to improve the frame, you can improve the size of the live photo, put filters, oar hdr and other photo modes and a thousand more. besides all so garlic and operation of the application in general, are very, simple. 5/5
Easily the best libre camera app on Android. Works decently well on a wide range of devices and allows plenty of customisation.
It's free, and free without ads. It has lots of functions.
It's Open Source, Free, and it has so many options you can tweak to your preference.