You can add or remove Apps from your Distraction Nudge list from within your Settings menu. To access this, go to Settings > App & Website Awareness.

Down the page, you will see Distractions. This is where you will find the Distraction Nudge panel which will allow you to add or remove apps from your Distraction Nudge List.
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In your Distraction Nudges section, you can choose which applications you would like to count as unproductive while flowing by hovering over the application and selecting "-" (minus).
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To add an application back into your Distraction Nudges, click the "+" (plus) button at the bottom of the Distraction Nudges Window.
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