This app is,
when you connect your headphones to your smartphone, the sound mode will change to Vibrate if Sound.
when you disconnect your headphones from your smartphone, the sound mode will change to Sound if Vibrate.
if you are trying to set Sound to the sound mode in state of connecting a headphones, then change to Vibrate.
That's all. If in the case of silent mode does not do anything.

When you are listening to the music by connecting the headphones, sounding E-mail notification sound is loud, don't you surprised?
When you connect your headphones to your smartphone, don't you think, "I wanna switch the sound mode to Vibrate."?
When you disconnect your headphones from your smartphone, don't you think, "I wanna switch the sound mode to Sound,"?
I have the good news for somebody like you!
Exactly, When you your headphones to your smartphone, the sound mode will change to Vibrate. When you disconnect your headphones from your smartphone, the sound mode will change to Sound. Just a simple app.
Although more sophisticated apps are a lot there.
But those are difficult to set up.
There's problem with my smartphone, that will be difficult to verify.
I wish only the more simple operation, so I thought always, and I tried to make it myself.

This app will continue to work in the background even if you close. To stop the operation, press the STOP button. To run again, please press the START button or launch the app again.

Attention!
For Android 6 or higher, tap the setting button and set the battery.
If you are using a task killer app, add this app to ignore list.

This app uses the internet access to display the ads and analyze.

Note: It is there to be a malfunction or unexpected behavior for some reason. Changing the manner mode, please re-check yourself. I assume no responsibility whatsoever for any damages resulting from the use of this app.