What is Application Owner within the GCP's IAM?

This is a custom role within Solvay to indicate the actual owner responsible for this GCP project. 
This application owner is expected to be awared of the resources and the uses of this GCP project.

This role is used by GCP Cloudops for the following:

1. Get approval on any requests on the assigned GCP project.
2. Notify on any security finding and require to follow up.
3. Access to the Billing dashboard

This role has no actual permission to change any resources within this GCP projects.
Any changes will be required to request to the Cloudops.

Permissions granted for this "Application Owner" role

• billing.resourceCosts.get
• logging.buckets.get
• logging.buckets.list
• logging.exclusions.get
• logging.exclusions.list
• logging.links.get
• logging.links.list
• logging.locations.get
• logging.locations.list
• logging.logEntries.list
• logging.logMetrics.get
• logging.logMetrics.list
• logging.logServiceIndexes.list
• logging.logServices.list
• logging.logs.list
• logging.operations.get
• logging.operations.list
• logging.privateLogEntries.list
• logging.queries.create
• logging.queries.delete
• logging.queries.get
• logging.queries.list
• logging.queries.listShared
• logging.queries.update
• logging.sinks.get
• logging.sinks.list
• logging.usage.get
• logging.views.access
• logging.views.get
• logging.views.list
• resourcemanager.folders.get
• resourcemanager.folders.list
• resourcemanager.organizations.get
• resourcemanager.projects.get
• resourcemanager.projects.getIamPolicy
• resourcemanager.projects.list
• securitycenter.findings.group
• securitycenter.findings.list
• securitycenter.findings.listFindingPropertyNames
• securitycenter.sources.get
• securitycenter.sources.list
• securitycenter.userinterfacemetadata.get

To better understand on the roles and permission, you can read from Google Documentation.