US Democratic Presidential candidate Barack Obama is to launch an application on Apple's iPhone to help recruit supporters.

Mr Obama's Call Friends application is seen as key to helping the Illinois senator win the all important swing states in November's election.

The software was developed in just three weeks by Mr Obama's campaign team and will help his supporters to become “more directly involved” in his bid to “change the country”.

Call Friends will track who is supporting which candidate and also sends users a voting reminder on election day.

People subscribed the application will also receive campaign news, video and photos to help encourage friends to vote for Mr Obama.

Mr Obama has continued to embrace new technology during his bid to become America's first black President. He faces Republican John McCain.

The Democrat's campaign has continued to attract support from musicians. See which stars have back Mr Obama HERE.