• by Mark Walsh  @markfwal, October 30, 2012

Internet radio service Pandora on Tuesday announced updated versions of its iOS and Android applications, offering expanded listening options, new artist pages, and timeline–focused user profiles.

The company has also partnered with several prominent brands including McDonald’s and Nike to help promote the launch of the revamped apps.

These steps come as Pandora faces the threat of Apple launching a rival ad-supported streaming music service. Bloomberg last week reported the tech giant may introduce the service as early as next year, sending Pandora’s stock tumbling on the news. Apple declined to comment on the report, which said the company is in licensing talks with Universal Music Group, Warner Music Group and Sony Music Group.

In the meantime, Pandora is upgrading its apps as its user base shifts rapidly from the desktop to mobile devices. More than 75% of its total listening hours now take place on mobile phones and other connected devices. And 115 million of its 175 million registered users have accessed the service on a smartphone.

Among the new features of Pandora 4.0 for iOS and Android apps:

Listening functionality: More prominent controls are designed to allow users to add more song variety, shuffle and rename stations, and view station details more easily. Streamlined navigation also lets mobile users for the first time browse the more than 400 genre stations available.

Artist Pages: Changes include improved artist biographies, album discographies, and music “genome” traits of the current track spinning.

Personal music profile: Provides a detailed timeline of Pandora listening for each user, showing music preferences such as stations created, bookmarked tracks, and history of “thumbs” up or down on selections. Listeners can opt to keep profiles private.

Music Feed: Offers a centralized place for listeners to find and follow friends and explore what listeners with similar musical tastes are discovering and enjoying on Pandora.

Social sharing features are also available on mobile for the first time, giving listeners the ability share links to favorite stations and songs on Pandora, Facebook and Twitter.

Pandora also noted that the changes provide for a uniform experience across both iOS and Android.

So what do users think? Based on ratings in the App Store so far, the new Pandora app isn’t quite up to the level of the old one. It's received an average of three stars --  based on only about 500 ratings to date -- compared to three and a half for the old app (based on more than 65,000 ratings).

Some  of the reviews posted suggested the app only displayed in portrait mode on the iPhone, rather than in landscape mode as well. But it’s not unusual for an app to have some bugs that need to get worked out following release.

To help market the updated Pandora app, the company has assembled an impressive lineup of brands -- McDonald’s, Nike, Sony Pictures and State Farm -- that are sponsoring user tips and information inside the app. Each brand will also launch mobile campaigns appearing in highlighted new social features of Pandora 4.0 in the coming weeks.

Separately, Microsoft said Tuesday that it would introduce a version of the Pandora app for its Windows Phone platform during the first quarter of 2013, throwing in a year of ad-free music to help entice users. Pandora 4.0 is now available in the App Store, and will be in the Google Play store in a few weeks following final testing on Android.