How to use this Utility Plug-in?
Since iMovie does not offer the ability to add Utilities, this Utility Plug-in is made as if it was an Effect. Though, you'll find the Join Clips Plug-in in the iMovie Effects tab.
Like iMovie, this Plug-in is really easy to use: you only have to select the first clip you want to join, select the SebSofts - Join Clips Effect from the Effects List (1), tell the Join Clips Plug-in how many clips you want to join (2), then apply! (3).