Most phones let you enable and disable forwarding to voicemail, but few let you specify the delay before voicemail is invoked. Setting that delay requires special codes to be sent to your network provider instructing the GSM system. Fortunately most of the world's providers use the same coding method.
The Internet Man is the developer of the app which can be found in the Tools category. Over 1K users set up Voicemail Delay and its latest update was launched on Aug 26, 2015. Google Play shows that this application is rated 3.4 by its users.
Get the setup package of Voicemail Delay 1.2 that is completely free of charge and check out users' reviews on Droid Informer. The app can be launched flawlessly on Android 4.0.3 and higher. The download of the app is safe and secure.