Speech Bubble

Speech Bubble is an instant messaging app used in Academy City. It allows users to add other users through their IDs. It doesn't have a username feature.

Dream Ranker Arc
Both Saten Ruiko and Frenda Seivelun used the app, which allowed them to communicate with each other after they met.

Jailbreaker Arc
After the Jailbreak Trial, Mei and Kii, two members of Shokuhou Misaki's Clique assigned to discretely protect Kouzaku Mitori and Dolly sent messages on the app to let Shokuhou Misaki know that the two were safe.