Reading the comments it seems to work well, but a few reported problems indicate that I need to further emphasize that that this small piece of software is a button widget only, there is no regular user interface that opens on installation or on click. There is just a widget added to the home screen menu. Put the widget button somewhere, touch it to start the vibration, touch it again to stop.
So, that being said, such an app obviously makes for quite uninteresting screenshots. But here they are, directly from the app market.