7. Water Reflection enables you to create an effect similar to a reflection in the water of your photograph. It will be added to Effects < Distortion.
8. Photoshop File Plugin - Open and edit Photoshop files in Paint.NET without having to change the extension.
9. Unsharp Mask is a classical method to increase edge contrast. You can use it for sharpening your photos. After installing, you'll find it under Effects < Photo < Unsharp Mask.
10. Color Replace is part of a plugin pack that contains several other effects such as Soften Edges, Focal Point, Stencil, Varicose, Bricks.