Bootmon (App Monsters)

Bootmon is an Appmon Leviathan is searching for unknown reasons. In the manga, he is Hajime Katsura's Buddy Appmon.

Anime
Bootmon is considered "the most important person" by Leviathan, who wants to find him. A picture of him is kept in a secret file in the Deep Web.

When looking for Hajime, Rei Katsura and steal files on people related to Leviathan, and finds Bootmon's picture, with the name partially obscured. On the same day, Leviathan orders the Ultimate 4 to look for him. When escaping from Leviathan, Rei and Hackmon stumble upon an image of Bootmon with his name intact. On the same day, Knight Unryuji asks Eri Karan to help him find Bootmon. It is later revealed that Hajime actually created Bootmon under Leviathan's orders, and sent him off into hiding the minute showed up.

Manga
Bootmon is Hajime Katsura's Buddy Appmon. His app was created by Hajime.