From Forum Nokia Wiki

If you have to find out the UID of all the application installed on your 3rd edition device then here is the way to do it .

Summary

The following code will display UID of all the application installed on the phone

It uses the following classes:

RApaLsSession iLsSession;
MAppUidObserver& iObserver;
RArray<TAppInfo> iApps;

class TAppInfo
        {
          public:
          TInt32 iAppUid;
          TApaAppCaption iAppCaption;               
        };

void CAppUidViewerEngine::AppsToUiL()
        {
           TApaAppInfo apaAppInfo;
           TAppInfo appInfo;
           iApps.Reset();
        // Get info on all apps, then iterate through each app
           User::LeaveIfError(iLsSession.GetAllApps());
           while(iLsSession.GetNextApp(apaAppInfo) == KErrNone)
                {
                appInfo.iAppCaption = apaAppInfo.iCaption;
                appInfo.iAppUid = apaAppInfo.iUid.iUid;
                User::LeaveIfError(iApps.Append(appInfo));
                }
 
        // iObserver.AppsFoundL(iApps);
        }

The above snippets will extract the UID of the application and Append it in and Array which will be passed to the view class for display