SharePoint 2013: Listing out Existing SharePoint App Pools http://stevemannspath.blogspot.com/2013/06/sharepoint-2013-listing-out-existing.html
[Microsoft.SharePoint.Administration.SPWebService]::ContentService.ApplicationPools | ft Name
[Microsoft.SharePoint.Administration.SPWebService]::AdministrationService.ApplicationPools | ft Name
Get-SPServiceApplicationPool | ft name