For easing Gcam Mods and its features, we have also prepared a handbook. If you want you can have a look or share to someone who needs it.

Guys There is no Auxiliary Camera on the last 8.2 Release. I'd add it soon. Please stop asking the same question 😅

Changelog:
1. Added Several new Noise Models, AWB Models
2. Added the ability to use JPEG VF and RAW Sensor. Search pck in developer settings.
3. Added Option to change Motion Photo and Viewfinder record Resolution (You can now record 12MP Video though the quality is average because of only viewfinder capture)
4. Corrected Sharpness, Chroma and Spatial Denoise addresses of Rampatcher and added Manual Patcher
5. Added Manual Patcher Override like upcoming Arnova 8.2 (Thanks to Arnova)
6. Slow-motion now works on OnePlus 7 series. Added camcorder capturerate and bitrate options to developer Settings
7. You can now change FPS from top menu bar in Video. (Thanks Arnova8G2). Enable 60fps from developer Settings if you want.
8. Added a new "Special Fixes" tab for several device specific fixes. You can enable/disable Sunbug fix, raw fix, digital gain fix from there. You can now use "Third party gallery" by enabling that option as well. Digital Gain Fix is needed for Samsung S9 series.

Yes and I know you are looking for aux but currently I am taking an exam which does matter to me more and am out of modding for sometime. After the exam ends at the end of this month, I'll be able to complete aux. And I would also fix for Camera2API Full Devices after that. I didn't want you all to wait that long for fixes already done so I am pushing the update already.

We have already figured out Face Retouching fix for some devices.

For OP8 series by Arnova8G2:
1. Enable pck.use_jpeg in developer settings

For OP7 series by SixArmedPriest:
1. Enable pck.use_jpeg, pck.raw_sensor, disable_hdrplus_postview and camera.wiener_force in developer settings. Set SM8150 Manual stream config for Front, Main and Portrait.

For OP Nord by me:
1. Enable disable_hdrplus_postview in developer settings. Set SM8250 Manual Stream Config for Front, Main and Portrait.

com.google.android.GoogleCamera.Cameight

It contains the bookmark addresses for manual patcher. The bookmark was prepared by-
@domonikNF
@ytsependa
@I_User_X
@ETALON

Julian Tsependa also prepared a google sheet to convert your values for use in gcam:
https://tinyurl.com/y5k3m5x5

Gcam 8.2 Update
Version 210627

- Added Support for Auxiliary Camera. Enabled by default on OnePlus 7T/Pro, OnePlus 8/T/Pro, OnePlus Nord/Nord CE, OnePlus 9/Pro, Galaxy S21U SD. IDs are set for Galaxy A52, A70, A71, A72 etc. Others can enable the AUX from Advanced Settings>Auxiliary Camera and IDs. If you happen to have wrong IDs, just change from manual camera IDs. Same goes for the button names.
- Separated Rampatcher, Custom AWB, NM, Stream Configs for different lenses.
- Added Support for several devices that had a black viewfinder on last version. Includes support for OnePlus Nord on Custom Roms with Pixel Props like Pixys, PE, and PeX Roms.
- Heavily improved Manual Rampatcher Logics. Now should work better and with less crashes. Here's a google sheet prepared by @ytsependa where you can get manual values and address prepared. To use the sheet, make a copy to your account and then wait for values to be loaded. Rest you can handle yourself. https://tinyurl.com/yz9vf5fv
- Added Option in Advanced Settings to show a sunset Button in viewfinder.
- Darkened the output from sunset mode. Now works better even without tap to focus.

The whole UI for Aux and Sunset Button was planned by @SavantCZ and I implemented them. Vertical AUX buttons have been a part of Greatness ecosystem for a long time right from Camstellar and that UI was also planned by Savant.

Package Name: I have provided three different package names.

1. com.google.android.GoogleCamera.Cameight: It's the main Greatness package name. Auxiliary Camera on Xiaomi, Realme, OnePlus 7 Series, 9 series and Nord series will work with this package name. No other developer has this package name, and you can install alongside other Gcam mods, so it's recommended. (Update to the latest OOS on OnePlus 9 Pro if you can't access telephoto)

2. org.codeaurora.snapcam: This package name is required only for OnePlus 8/T/Pro. Sadly this series can only have working aux with this package name and several developers use this package name.

3. com.samsung.android.biometrics.service: It is required for accessing the 3rd Back Camera usually telephoto or Macro on any Samsung devices. Good that other developers don't use this package name so can be installed alongside other Gcam mods.

In a nutshell, if you ask which one you should install, here's the rule of thumb:
1. OnePlus 8/T/Pro: org.codeaurora.snapcam
2. Samsung: com.samsung.android.biometrics.service
3. All other phones: com.google.android.GoogleCamera.Cameight

Very Beautiful Changelog:
Version very beautiful

- No apk comes associated with this Changelog
- I forgot what changes I did
- I did very important changes
- The changes are unprecedented
- Apk will be released soon
- But I don't know what to write in the Changelog
- That's all for tonight

Gcam 8.2 Update
Version 210716

- Added manual Viewfinder FPS Range. Thanks Wichaya for helping to understand. These are separated per modes and lenses.
- Separated Motion Res per lens
- Added Background Processing Check for every restart activities. Now app won't restart and destroy the image under processing
- Added more options (multipliers) in ISO/Exposure Time Control (Thanks @ytsependa )
- Fixed Telephoto lens name on S21U, Added the default IDs for S20FE and enabled aux by default on them
- Separated Manual Patcher Override per lens
- Added new options dev settings. Search model, special and others are easter eggs. They unlock special settings in Advanced Settings>Special Fixes page. Jpg configs and HDR Models are notable among others.
- If VF button for sunset mode is enabled, the settings toggle is now hidden
- Sunbug Fixes are embedded for Sunset Mode. Includes the fix for Samsung and OnePlus both.
- Added Mi10Ultra NMs
- Added Chinese Simplified Translations (Thanks Skiing)
- Added Maximum Frames option (has possibility of frame drops so, medium or high is recommended)

If Astrophotography doesn't save on any 8 Series device, disable camera.pck_use_jpeg.

The sunbug fix for Samsung A52 phones is
a52sunbugfix;0210243C=E803271E

Original fix was found for 7.3 by XDA Senior Member txx1219 but Julian got me the address for 8.2. You can use the bug fix by putting the fix in manual patcher override.

And finally sorry Note10+, S10+ and Mi10Ultra guys. Couldn't fix your issues and also people with API 2 Full guys. It's difficult fixing without having the device and I am still COVID Positive so couldn't spend much effort on it.

And finally a reminder of package name confusion:
1. OnePlus 8/T/Pro: org.codeaurora.snapcam
2. Samsung: com.samsung.android.biometrics.service
3. All other phones (including OnePlus): com.google.android.GoogleCamera.Cameight