It’s Fathom Mono for you - and it’s free!
Fathom Mono is a free, monophonic version of the Fathom Synth - for the full version of this awesome synth, go to www.fathomsynth.com. Download user manual here Fathom provides the tools necessary to realize virtually any waveform. This includes a free-hand drawing tablet and exponential and Bezier curves. The GUI supports wave editing as an art form with views that expand to fill the entire interface when they are selected. Fathom is a great option if you use waveform libraries such as AKWF and Galbanum and want to make edits to the waveforms.