I doubt there are any tutorials for a masking app (could be wrong). The key to masking apps is to get a real clear understanding of the tolerances that you apply to your masking brush. None of them really have "magic brushes". You still need to do a lot of brush tweaking if you have a complex job. I got so tired of it I finally abandoned them altogether and just stick with Quick Mask channel selections and vary my brush size alot. It may bit a little slower going but it's a lot more direct. I know at all times what I'm painting out and what I'm not whereas with the masking apps it just seems to be endless tolerance tweaking. Incidentally I've used both Knockout and Maskpro and agree with above, MaskPro is better but again, is no silver bullet.