The Gummiphone is a gameplay feature in Kingdom Hearts III.
Kingdom Hearts III
The Gummiphone is a phone made up of Gummi Blocks, allowing for communication across different worlds. Its been a project of Chip and Dale's some time before Dream Drop Distance and completed by 2.9. One was given to Ienzo, while one went with the King and Riku. One was given to Sora, who found it in his new clothes; Chip, Dale and Ienzo brought Sora up to date on Ansem's Code and asked Jiminy to teach Sora how to use it.
After saving Hayner, Pence and Olette from a Demon Tide, Sora gets the idea to take a photo with them. However, he goofs up and initially believe the camera worked on a timer. Goofy takes with picture, with a scowling Donald included with the quartet. Olette sees a Lucky Emblem in the background, which Sora, Donald and Goofy recognizes as the King's symbol.
When attempting to access the virtual Twilight Town, Sora gets a call from Ienzo, who was alerted that someone was trying to access the DTD from another computer. Talking with Pence over the Gummiphone, Ienzo establishes a link with both computers, allowing him more data to crack the Code and reconstruct Roxas' heart.
Sora attempts to call Ienzo to find out about getting a body for Roxas' heart. However, he gets the King and Riku instead; they fill him in on replicas, while Sora updates them on Maleficent and the Organization's search for the Black Box.
Having grown impatient with not regaining the power of waking, Sora considers calling Riku to find a way into the Realm of Darkness. Ienzo calls, revealing a portion of Ansem's Code states three hearts reside within Sora's heart. After their recent run in with Vanitas, Goofy decides the second heart belongs to Ventus; though Sora is clueless who the third heart is.
After arriving in San Fransokyo, Sora attempts to call Riku to tell him how amazing the sights are. However, he is stopped by a Heartless attack.
Having lost contact with the King and Riku in the Dark World, a concerned Chip and Dale call Sora to tell him the news. As the trio debate over how to go help, Chip and Dale explain that the King could get into the Dark World because his Keyblade came from that realm.
Aqua, Ventus, Kairi, and Lea are later given Gummiphones with summaries about everything that has happened in the last decade to help clear up confusion. Ienzo later lends his Gummiphone to Demyx to be used as proof he is on the Guardians of Light's side while looking for replicas at the Keyblade Graveyard.
The Gummiphone contains two cameras, a microphone, and the ability to communicate between worlds. Sora can use it to make video calls between worlds, like a normal smartphone. In gameplay, Sora can take pictures, scan QR codes in order to download Classic Kingdom minigames, and read Jiminy's Journal, which is now digital and maintained by Jiminy Cricket on the phone itself.