"WDR Rundfunkchor Sing Along" is a free Android app that allows everyone to sing with the WDR Radio Choir. It offers features like a customizable mixer, sheet music for all voices, and warmup videos from professional singers, making choir rehearsals accessible at home. Users can practice with conducting videos, metronome tracks, and detailed song information, while enjoying a diverse repertoire from classic choral literature to new arrangements. Perfect for choir enthusiasts of all levels!