Just one day after Spotify launched its iPad application, American-based rival Rdio has arrived in the UK and France, offering a similar service of unlimited music streaming to PC, Mac, Android, BlackBerry, Windows Phone and iOS.

Rdio

Rdio (pronounced arr-de-oh) is free to download and set up, giving you access to a catalogue of more than 15 million tracks. While you do get some free access to streaming music, it seems to be a bit convuluted as to how much access you get.

When we signed up today [3 May, 2012], we were told we will get seven days unlimited streaming through the Rdio website. There are no ads between songs but once the seven days is up you will be forced to stump up some cash.

Signing up is simply a matter of entering an email and a couple of other details, but crucially no credit card up front - which you will have to enter if you want to access Spotify Premium's free 30-day trial.

Rdio - which is the brainchild of Skype founder Janus Friis - has two paid options; £4.99 a month gives unlimited streaming through your internet browser while the more expensive £9.99-a-month adds unlimited streaming to all of Rdio's mobile apps (Android, iOs, BlackBerry, Windows Phone 7), desktop apps (PC and Mac) plus Sonos and Roku devices, too.

Rdio

These prices are the same as Spotify, but Rdio has the extra benefit of a web browser interface, so you can log in to your account through the company's website if you're on a computer without the application installed.

With the £9.99 package users can sync music to their smartphone or tablet and listen offline, meaning that there's no need to run up a huge mobile broadband bill, as music can be stored on the device locally.

Rdio users can build an unlimited number of playlists and 'follow' each other to browse users' music collections and listening history.

No matter how you browse the internet or what mobile device you have, Rdio has just about every base covered; the website works in Chrome, Firefox, Safari and Internet Explorer 8 and upwards - also for the desktop there are PC and Mac applications.

For mobiles, Rdio works on iOS, Android, BlackBerry and Windows Phone - but perhaps more interestingly is Rdio's functionality with Sonos and Roku home entertainment systems, as well as the iPad and wireless speakers with Apple AirPlay.