Whats the point?

Nothing new here. The "masking" is just the same noise / rain sounds that you can find in any of the many relaxation apps around for 99c! The only difference is that the volume of the sound is dynamically controlled BUT as this takes time, the volume increase is always after the sound event so the program is not good at masking random external sounds.
The harmonic masked would be a great relaxation tool if it wasnt for the many pops and clicks in the sound.
Stick to something like Ultimate Relax etc. - theyre better and more useful apps.
Can I have my money back?

HomeyJay about SoundCurtain