A free app for Android, by Darko Bunic.
Do Not Disturb is a popular application that allows you to set a time for your phone to go silent or to use a voice-based alarm. This is useful for people who have to stay focused during meetings or classes. It can also be used for those who have to stay focused and quiet during a conversation with a friend or family member.
This app is useful for meetings and classes, but it can also be used for other purposes. For example, if you have to stay focused during an important conversation, you can use this app to turn off your phone.