Customize Application is part of the System Administrator profile.
Be careful giving this permission to any other users.
Salesforce Indicators Permission Set
Assign the Indicators Setup Access permission set to any System Administrators who will be setting up SalesforceIndicators.
This grants access to the Indicators Setup Tab.
User Permissions
Assign the Indicators User Access permission set to any users who will be viewing Salesforce Indicators.
This gives the user the access to the Apex Class that returns the data to the Indicator Bundle and Indicator Item.
Once the Indicator Bundle is added to the Lightning page, all users who can see that page can see the bundle, unless it is hidden by Component Visibility.
Users will only see the Indicator Items if they have read access to the field and sObject the Indicator Item is based on.
Test your Indicator Bundles to ensure that there are no blank bundles, which doesn’t look good for users.
About Custom Metadata
See this Trailhead Module to learn more about Custom Metadata in Salesforce.