O2 has followed up on its early promise and brought its O2 Tracks application to Windows Phone. Available for free on the Windows Phone store now for Windows Phone 8 and Windows Phone 7.5, the app is powered by MusicQubed and offers all of the songs on the UK's Official Top 40 Chart plus 20 of the most popular others for you to listen to, even offline.

What it does is download all 60 tracks when the chart is announced each week to your phone so you can listen to them wherever you are. And you can listen to the Top 40 with no limits on the number of plays.

In addition, O2 Tracks offers celebrity gossip, playlists and more.

You don't need to be an O2 customer to use O2 Tracks, although it is cheaper if you are. You get eight weeks of free access when you first sign up if you are with O2, two weeks if you're not. Then it is £1 a week for O2 subscribers, £4.99 a month for non-O2 customers. O2 customers can pay through their regular bills, non-O2 users can pay by credit card, debit card or PayPal.

The Windows Phone version joins existing apps for iOS, Android and BlackBerry and is available from the Windows Phone store now.