BW-Plus is the simplest of all of these filters to use, but this doesn't stop it producing some striking results. The effect attempts to replicate black and white film photography using colored filters on the lens.
This works by just selecting from the drop-down list of different filters or just a straight conversion without a filter. The final result will vary dramatically depending on the colors contained in the original photo. You can see how striking the red poppies appear in my example image using the Red filter.