Get IIS Application Id & name

// Snippet        
using (ServerManager serverManager = new ServerManager()) { 

var sites = serverManager.Sites; 
foreach (Site site in sites) { 
         Console.WriteLine(site.Name); // This will return the WebSite name
}
// Start all stopped WebSites using the power of Linq :)
var sites = (from site in serverManager.Sites 
            where site.State == ObjectState.Stopped 
            orderby site.Name 
            select site); 

        foreach (Site site in sites) { 
            site.Start(); 
        }
using System;
using System.IO;
using System.DirectoryServices;

class Class
{
    static void Main(string[] args)
    {
        DirectoryEntry entry = FindVirtualDirectory("<Server>", "Default Web Site", "<WantedVirtualDir>");
        if (entry != null)
        {
            Console.WriteLine(entry.Properties["AppPoolId"].Value);
        }
    }

    static DirectoryEntry FindVirtualDirectory(string server, string website, string virtualdir)
    {
        DirectoryEntry siteEntry = null;
        DirectoryEntry rootEntry = null;
        try
        {
            siteEntry = FindWebSite(server, website);
            if (siteEntry == null)
            {
                return null;
            }

            rootEntry = siteEntry.Children.Find("ROOT", "IIsWebVirtualDir");
            if (rootEntry == null)
            {
                return null;

            }

            return rootEntry.Children.Find(virtualdir, "IIsWebVirtualDir");
        }
        catch (DirectoryNotFoundException ex)
        {
            return null;
        }
        finally
        {
            if (siteEntry != null) siteEntry.Dispose();
            if (rootEntry != null) rootEntry.Dispose();
        }
    }

    static DirectoryEntry FindWebSite(string server, string friendlyName)
    {
        string path = String.Format("IIS://{0}/W3SVC", server);

        using (DirectoryEntry w3svc = new DirectoryEntry(path))
        {
            foreach (DirectoryEntry entry in w3svc.Children)
            {
                if (entry.SchemaClassName == "IIsWebServer" &&
                    entry.Properties["ServerComment"].Value.Equals(friendlyName))
                {
                    return entry;
                }
            }
        }
        return null;
    }
}