BTS BT21 Onet Connect is a free Android app developed by Dinostudio01. It is a fun and colorful brain game that features images of BT21 characters - RJ, CHIMMY, COOKY, KOYA, SHOOKY, TATA, MANG, and VAN - inspired by the popular K-Pop group, BTS. The game is lightweight and can be played offline, making it perfect for passing the time while on the go.

The objective of the game is to connect two squares of the same shape to score points. BTS BT21 Onet Connect has 16x8 squares (128 tiles), and your score increases rapidly as you connect more shapes. The game interface is colorful and engaging, making it a great way to challenge your friends and compete for the highest score. However, it's not an easy task, and you'll need to use your brain to progress through the levels.