This is a Unity plugin for a native android plugin that will allow native control over the android vibration API
This is useful because Unity's default handheld device vibration is somewhat lacking for more complex vibration patterns (for what I assume is good reason, seeing that cross platform vibration is probably a huge pain in the butt).
What I have done here is write a wrapper around a the Vibrator class to allow all of the normal functionality for Android developers in Unity.
If you want the source code of the actual Android library that I made, then you can get it here.
After importing the plugin, you are going to need to give your app permissions to use vibrations in the AndroidManifest.xml. I found that the easiest way to do this is to build your app, and then head to Temp/StagingArea/ where you will find AndroidManifest.xml. Copy this file to your Assets/Plugins/Android, and then add the permission to that file. Now Unity will use that manifest file instead of the one in the staging area. Here is the permission to add:
<uses-permission android:name="android.permission.VIBRATE"/>
If you need to learn more about how manifest files work, then head to Google's documentation on it.
If you are using the plugin then note that it has a manifest in there already, and you need to make sure you update it with the proper information or replace it.
AndroidVibration is a static class that will allow you to make simple calls like AndroidVibration.Vibrate(100) to vibrate the phone. If you want to interface directly with the .jar then I have also exposed that through the VibrationPlugin field.
There is a simple example file under VibrationExample