Harp Sound Effect Plug-in is a free multimedia plugin developed by Rev Soft Inc. It is designed to work with two apps, Perfect Piano and Walk Band, and cannot be used alone. The plugin adds a new harp instrument sound to the apps' existing sound library.

To use the plugin, users need to enter the keyboard screen of either Perfect Piano or Walk Band and select the switch instrument icon. The harp instrument icon will automatically appear, and users can select it to load the new sound. The plugin is easy to use and adds a new dimension to the music-making experience.

The plugin comes with a notice that suggests users change the sustain time through the app settings to make the sound more comfortable. If users encounter any issues while using the plugin, they can contact Rev Soft Inc at

Overall, Harp Sound Effect Plug-in is a useful addition to Perfect Piano and Walk Band for users who want to experiment with new sounds and enhance their music-making experience.