Rose Tyler's mobile phone
Rose Tyler owned multiple mobile phones.
History
On 5 March 2005, Rose called her mother Jackie Tyler whilst the Ninth Doctor confronted the Nestene Consciousness, warning her to leave town. Jackie, however, told Rose that she was breaking up and so proceeded to go shopping. Later that night, Jackie, having survived the Auton attack, called Rose to warn her to stay at home, only for Rose to hang up without saying a word. (TV: Rose)
The Doctor altered Rose's mobile phone into a superphone by adding a chip into it, enabling Rose to call Jackie while on her travels with him. Rose had experienced distress at the thought of going to a time period where her mother would quite likely be long dead by then, which prompted the Doctor to modify her mobile to contact Jackie in real time elapsed from the point she entered the TARDIS. (TV: The End of the World)
In September 2006, Rose used her mobile phone on speed dial to co-ordinate the pursuit of Blon Fel-Fotch Passameer-Day Slitheen, then disguised as Lord Mayor of Cardiff Margaret Blaine, with the Doctor, Mickey Smith and Captain Jack Harkness. (TV: Boom Town)
After the Lady Cassandra took possession of Rose's body on New Earth, she received a call from the Tenth Doctor on Rose's superphone and initially believed the ringtone was coming from her posterior. Encouraged by her servant Chip, who described the phone as a "primitive communications device", Cassandra answered the call with an attempt at "Old Earth Cockney" rhyming slang to pass herself off as Rose and assured the Doctor she would be on her way. (TV: New Earth)
While stuck in Pete's World, Rose's superphone still worked. She used it to find out about that parallel universe. During the invasion of the Battersea Power Station, the Doctor had Mickey find the code to disable the Cybus Cybermen's emotional inhibitors. He transmitted it to Rose's phone via text. The Doctor plugged the phone into a nearby console and the code shut down the inhibitors, destroying the Cybermen at the station. The Doctor had Mickey keep Rose's superphone, as it had the code he needed programmed into it. (TV: The Age of Steel)
Rose received another superphone by the time she was stranded on Krop Tor. This phone had no signal there, after the TARDIS was briefly lost, but was intercepted by the Beast, who sent a message saying, "He is awake." (TV: The Impossible Planet)