Yes.

On the iOS app:

• Press Disarm, Arm Away or Arm Stay as appropriate to your situation.
• When the app prompts for a user code, enter the Duress code. 
• Press Done

On the Android app:

• Press Disarm, Arm Away or Arm Stay as appropriate to your situation. 
• When the app prompts for a user code, enter the Duress code. 

Setting the iOS app to prompt for a user code

• Touch More
• Open My Profile
• Slide the Prompt for user code switch to On
• You may be required to enter your user code after changing this setting
• Don't forget to SAVE the change you've made

Setting the Android app to prompt for a user code

• Touch the menu
• Select Settings
• Select Security
• Slide the Prompt for user code switch to On
• You may be required to enter your user code after changing this setting
• Don't forget to SAVE the change you've made