Short answers, pulled from the story.
Tower of God was created by Lee Jong-hui, known by the pen name S.I.U. (Slave In Utero). It launched on Naver Webtoon on the 30th of June 2010 and received official English translations from Line Webtoon beginning in July 2014.
As of February 2020, Tower of God had accumulated 4.5 billion views worldwide. The series was also being read by five million people per week as of July 2015, according to the head of Line Webtoon.
Twenty-Fifth Bam is the main character of Tower of God. He is an Irregular, meaning he opened the Tower's sealed door from the outside without being chosen, which is extremely rare. He enters the Tower to follow his only companion, Rachel.
Shinsu, roughly translated as Divine Water, is a substance found throughout the Tower in varying concentrations. It can enhance physical abilities and manipulate elements; users measure their control through three values called Bang, Myeon, and Soo. Strong Shinsu users age so slowly they become effectively immortal.
Two anime seasons have aired. The first was produced by Telecom Animation Film and directed by Takashi Sano, airing from April to June 2020. The second was produced by The Answer Studio and directed by Akira Suzuki, airing from the 7th of July to the 29th of December 2024.
Several mobile games adapt Tower of God. A role-playing game developed by Sunrise launched on Google Play in 2013, drawing 120 million players shortly after release, with a full commercial release in 2016. Tower of God: Great Journey by Ngelgames released globally on the 14th of February 2023, and Tower of God: New World by Netmarble released globally on the 26th of July 2023.