Added Get-DeviceStatusForApp function (#122)

I have added an extra function that gets all devices and their install status that are assigned to an application

Author: stgrdk

Applications/Application_InstallStats.ps1

@@ -216,7 +216,7 @@ Function Get-InstallStatusForApp {
 .SYNOPSIS
 This function will get the installation status of an application given the application's ID.
 .DESCRIPTION
-If you want to track your managed intune application installaion stats as you roll them out in your environment, use this commandlet to get the insights.
+If you want to track your managed intune application installation stats as you roll them out in your environment, use this commandlet to get the insights.
 .EXAMPLE
 Get-InstallStatusForApp -AppId a1a2a-b1b2b3b4-c1c2c3c4
 This will return the installation status of the application with the ID of a1a2a-b1b2b3b4-c1c2c3c4
@@ -263,6 +263,59 @@ param
 
 ####################################################
 
+Function Get-DeviceStatusForApp {
+
+<#
+.SYNOPSIS
+This function will get the devices installation status of an application given the application's ID.
+.DESCRIPTION
+If you want to track your managed intune application installation stats as you roll them out in your environment, use this commandlet to get the insights.
+.EXAMPLE
+Get-DeviceStatusForApp -AppId a1a2a-b1b2b3b4-c1c2c3c4
+This will return devices and their installation status of the application with the ID of a1a2a-b1b2b3b4-c1c2c3c4
+.NOTES
+NAME: Get-DeviceStatusForApp
+#>
+	
+[cmdletbinding()]
+
+param
+(
+	[Parameter(Mandatory=$true)]
+	[string]$AppId
+)
+	
+	$graphApiVersion = "Beta"
+	$Resource = "deviceAppManagement/mobileApps/$AppId/deviceStatuses"
+	
+	try
+	{
+
+		$uri = "https://graph.microsoft.com/$graphApiVersion/$($Resource)"
+		(Invoke-RestMethod -Uri $uri -Headers $authToken -Method Get).Value
+
+	}
+	
+	catch
+	{
+		
+		$ex = $_.Exception
+		$errorResponse = $ex.Response.GetResponseStream()
+		$reader = New-Object System.IO.StreamReader($errorResponse)
+		$reader.BaseStream.Position = 0
+		$reader.DiscardBufferedData()
+		$responseBody = $reader.ReadToEnd();
+		Write-Host "Response content:`n$responseBody" -f Red
+		Write-Error "Request to $Uri failed with HTTP Status $($ex.Response.StatusCode) $($ex.Response.StatusDescription)"
+		write-host
+		break
+		
+	}
+	
+}
+
+####################################################
+
 #region Authentication
 
 write-host