Samsung S4 And Samsung galaxy Note2 (Hidden camera )

• Go to setting  
• Tap on lock screen 
• select lock screen options 
• scroll down you can see wake up screen you have turn it ON

• Tap on  wake up command 
  
• U have to set a wake up s voice 
• You can also change by selecting 
  
• You can also change the command
  
  
  
  
   
• Selecting S voice under the menu option.
• Scroll down u can see the control apps turning it ON.
• Again tap on the control app u have to turn it on this will enable to Take the photos enabling by voice command.
• keep your phone in silent mode.   
• Then check what the command you have recorded given to take a photo.