Where is the Developer options in the Settings on the S6? On the S3 it was easy to find. I clicked on everything under Settings.  I can't find it. Where do I access it?
Follow the instructions:


Go to Settings &rarr; About device.  
Tap Build number 7 times.  

After tapping build number two or more times, a toast will be shown on the screen telling you the progress:


  You are now X steps away from being a developer.


After tapping the build number 7 times, you will be notified you are a developer. 

Now, Galaxy S6 developer options will be available in the Settings menu. 

(Click image to enlarge)



Go to Settings &rarr; Developer options.  
In the Settings menu, you can find the Developer options right above About device.  Tap Developer options.  
Enable Galaxy S6  Developer options.  
In Developer options page, drag the switch to right to turn it on. The color should change to green as shown below.  
Use Galaxy S6 Developer options.

For example, you want to turn on USB debugging on Galaxy S6. You can tap USB debugging as shown below. This will enable USB debugging for Galaxy S6.  





Full list of Galaxy S6 developer options


Take bug report
Set desktop backup password
Stay awake while charging (screen will not sleep)
Bluetooth HCI snoop log
Processes stats (lists the stats of running processes)
USB debugging (you can then run ADB command from PC)
Revoke USB debugging authorizations
Include bug reports in power menu options
Allow mock locations
View attribute inspection
Select app to be debugged
Wait for debugger
Verify apps vis USB
WiFi verbose logging
Aggressive WiFi/cell handover
Allow WiFi roaming scans
Buffer size for logging
Show touches
Show pointer location
Show screen updates
Show layout boundaries
Force RTL layout
Window animation scale
Transition animation scale
Animator duration scale
Simulate secondary displays
Force GPU rendering
Show GPU view updates
Show hardware layers update
Debug GPU overdraw
Show non-rectangular clips
Turn on 4x MSAA
Turn off hardware overlays
Simulate color space
Use NuPlayer (instead of AwesomePlayer)
Prevent USB audio routing
Strict mode
Show CPU usage
GPU rendering profile
Turn on OpenGL traces
Do not keep activities
Limit background processes
Show all ANRs (app not responding)