Playback Mic is a free Android app designed for various audio-related tasks, particularly for training vocal projection and language pronunciation. The app allows users to output audio from the microphone to speakers or headphones, offering features like custom delay on monitoring, audio recording in both compressed and uncompressed formats, and quick replay and sharing of the latest recorded files. It is ideal for users practicing casting, testing headphones, or recording with audio monitoring.

While the app provides a useful feature set, it is not suitable for use as a singing microphone with loudspeakers or as an interface with near-zero latency due to inherent limitations of Android devices. Users are advised to use headphones to prevent feedback loops during monitoring. The free version allows for 3 hours of total recording or monitoring time, after which sessions are limited to 1 minute.