Horror 666 Soundboard is a free Android app developed by One Suro Media. It is a collection of horror soundboard sounds that can be used to prank your friends or to create a spooky atmosphere during Halloween. The app consists of several types of scary ghost soundboards, including pennywise, siren head, huggy wuggy, and many more.

Using the app is very easy, just choose the ghost sound prank you want to play, tap the scream soundboard button, and enjoy. You can also download the sounds for free and use them as ringtones. The app is not tied to any other app and is meant solely for entertainment purposes.

Overall, Horror 666 Soundboard is a great app for scary sound for Halloween pranks. The sound quality is good, and the selection of scary sounds is impressive. However, some users may find the app too scary, so it's best to use it with caution. If you're looking for a fun way to scare your friends during Halloween, then this app is definitely worth a try.