Undecember is an Android app developed by LINE Games (2F, 218, Teheran-ro, Gangnam-gu, Seoul, Republic of Korea06221). Others apps created by LINE Games are: Brave John, Dragon Flight, Exos Heroes.

Undecember first became available on 13 Oct 2021. It is estimated that Undecember has been downloaded between 100 and 500 times from the Play Store.