justbeforepresenting.ps1

$apps = @('viber','skype','lync','outlook','spotify')

$forceclose = @()
$procs = get-process
foreach($kp in $apps) {
    $procs | ? { $_.name -imatch $kp } | % {
        $proc = $_
        $result = $proc.CloseMainWindow()
        if ($result -eq $false) {
            $forceclose += $proc
        }
    }
}

if($forceclose.count -gt 0) {
    start-sleep -Seconds 2
    $forceclose | % {
        $_ | Stop-Process -Force -PassThru
    }
}

start-sleep -Second 2
$procs = get-process
foreach($kp in $apps) {
 $procs | ? { $_.name -imatch $kp }  | Stop-Process -force
}