This app has no ads, no adware, no spyware, and does not "call home" in any way. It is 100% free. Just for you; just because we're friends.

When enabled, if you manually set your phone to 'silent mode' or 'vibrate only mode', an interface will slide down from the top, allowing you to tap a button to quickly set Silent Timer for 5 minutes, 10 minutes, 15 minutes, all the way up to 8 hours.
For more granular control, you can also use the slider to select precisely how long Silent Timer should wait.

At the end of the timer duration, sound will automatically be re-enabled.

Silent Timer is great for when you're at a doctor's office, on a date, or at the movies. Just silence your phone, and tap the button corresponding to the expected duration of the event.

For example, I might press '2 Hrs' or '2.5 Hrs' if I'm seeing a movie, to make sure that my sound is automatically re-enabled afterward, and I don't miss any calls or important notifications if I forget.
If I re-enable my sound at any point before Silent Timer does, it will recognize that and not make any changes.

Silent Timer can also disable wi-fi and/or sound when in range of a given network (say, a network around where you work!) and re-enable them when you leave the area. See the video for more details, and a demo.