For the specific Spanish translation by DragonTranslation, most readers use:
Since your text mentioned "APK," here are the best ways to read on mobile: Popular open-source readers where you can add extensions
📌 Chapter 91 is a pivotal part of the Yu vs. J buildup/fight arc. If you can't find it under "Chapter 91," check if it's listed as Season 2, Episode 91 . The most popular Spanish manga/manhwa aggregator
Popular open-source readers where you can add extensions (like TMO or LectorManga) to read everything in one place. Episode 91 .
You can read "The Boxer" officially on Webtoon . Note that chapter numbering might differ slightly due to "Free" vs "Fast Pass" releases.
The most popular Spanish manga/manhwa aggregator. LectorManga: Often shares the same database as TMO. 📱 Reading on Android
Available on the Play Store for the official experience.