Sing in Key, developed by Westkull Studios, is a free Android app designed for aspiring singers who want to improve their vocal skills. It is a user-friendly app that helps users to sing in tune by providing real-time feedback on their pitch. The app is categorized under Multimedia, specifically Music & Radio.

The app is very simple to use. Users can select their desired scale using the notes toggle buttons and start singing. The notes turn green if the user is in key and gray if they are out of key. With its super-sensitive pitch detection, the app provides users with accurate feedback on the exact pitch they are singing. Users can achieve a green score of 90% or more to assure themselves that they are singing in tune.