From today (9 October), fans will be able to download six interactive 'pet rival' characters - three boys and three girls - directly to their handset.
The Tamagotchi-like fictional characters, called JD, Gaz, Bo Nidel, Baby Belle, Sugar and Mad Dona, embody various pop styles and fashions.
They can refer to users by name, tell jokes and play games such as noughts and crosses with users. They also need to be given food and drink.
Getmedia, the mobile entertainment service provider, will supply the product.
The characters will be promoted on the Popstars web site (www.itv.com/popstars), where users are asked to text message their details to a phone number to receive a 'pet'.
Users who dial the number are charged 拢1 a minute for the call, which can last for up to three minutes. Granada Interactive will share revenues from the initiative with Getmedia.
In keeping with the rivalry theme of the show, users can give their character a score based on entertainment value.
Getmedia will update pet responses to reflect each one's particular 'pop style'.
Simon Howship, business development director at Getmedia, said: "We were briefed to offer the Popstars: The Rivals audience yet more mobile entertainment fun."
The ITV show has also developed a chatroom with ISP Lycos and pay-to-play games on its site with Littlewoods Leisure.