The offline mode allows you to suspend the development of photos in HDR until the mode is deactivated. 

This is useful in a case where you don't want to use your cellular data to develop photos and you want to wait until you are on a WiFi network. 

To activate/deactivate the offline mode 

1) Open the Exposio Rea Estate Camera app

2) Click on the menu button in the upper right corner

3) Click on Settings

4) Activate/deactivate the Offline mode