21 Dressroom is a free-to-use lifestyle shopping app developed by PoWeRMoBiLe.kr. It has a members-only feature that provides real-time push notifications for various events, sales, and benefits. It also offers easy login and authentication for hassle-free shopping, even for non-members, who can enjoy discounts and earn rewards by simply registering with their email address and ID. Users can invite friends to join and receive various benefits such as coupons and cashbacks. The app also features an auto-review function that automatically prompts users to write reviews of their purchased products. Additionally, it offers one-touch delivery tracking and a mobile membership card for offline shopping. The app requires certain access permissions for device identification, file upload, and push notifications.