Timer Voice Recorder is a paid Android app that allows you to record sound secretly and stop recording automatically. It is developed by Han Chang Lin and is available for free. The app comes with a timer setting and a range of useful features that make voice recording easy and hassle-free.

One of the most impressive features of this app is that it allows you to record sound under the screen off. It also offers unlimited recording length, making it perfect for recording long conversations or lectures. The app uses high compression technology, which means that 1 hour of recording takes up only 8 MB of space on your device. Other features include auto-repeat playback, auto-stop timer, password setting, and background recording.

To use the app, you simply need to assign a record number using the front and back buttons, set the countdown timer in seconds, and press the top switch to start recording. You can even turn off the screen while recording. After recording, you can enter a mark text and press the save button. The voice bottom toolbar allows you to control playback.