Add-PSSnapin Microsoft.SharePoint.PowerShell

$poolName    = 'Service Applications' # leave blank to get all app pools on the server
$serverNames =  Get-SPServer | ? { $_.Role -ne "Invalid" } | % { $_.Name }

Invoke-Command -ComputerName $serverNames -ScriptBlock  {
    param
    (
        [parameter(Mandatory=$false)][string]$PoolName
    )

    Import-Module WebAdministration;

    foreach( $state in Get-WebAppPoolState -Name $PoolName )
    {
        [PSCustomObject] @{
            Server  = $env:COMPUTERNAME
            AppPool = $state.ItemXPath.Replace( "/system.applicationHost/applicationPools/add[@name='", "").TrimEnd("']")
            Status  = $state.Value
        }
    }
} -ArgumentList $PoolName | SORT Server | FT Server, AppPool, Status -AutoSize