The Google mobile Apps for Windows phone can now be downloaded by visiting m.google.com from the browser of your windows phone.
Basically, the Google mobile Apps for windows phone provides you the opportunity for doing Google search from your mobile phone without the need of opening a browser and loading the Google homepage. Besides, the Google App also renders you a one-click access to any other mobile products of Google such as Google Maps or Gmail for your mobile phone. Furthermore, it can also be configured with your Google Apps account.
Presently, the Windows mobile phones support the Google App having a software version of 5.0 or above. So, if you are unable to download the link from m.google.com, then your mobile phone is not compatible with the Google App and you need to upgrade it soon!