Absolution: Chapter One
Also available as: Android mod
Most mods install on top of a fresh copy of DDLC, free from ddlc.moe. Follow the author's instructions, and keep a clean copy of the game.
About this mod
In a world of supernatural powers, one person who finished playing DDLC wanted to use his powers to enter the DDLC world himself. He was willing to change the outcome and resist Monika's influence to get a good ending where he could save the girls. This alters the story a lot, as he replaces the main character with himself and will now have to face all the girls' troubles.