https://play.google.com/store/apps/details?id=com.fgnm.baconcamera
It has the following limitation:
- No RAW support
- No Manual Focus support
- No Manual White Balance support
- No exlusive OnePlus One support (Clear Image etc.)
If you like it, please consider to buy the standard version with many other improvements and awesome features for your device!
Open Source Licenses:
https://github.com/sultanxda/android_packages_apps_SnapdragonCamera/
https://github.com/troop/FreeDcam