Amazing – I have Helix on my shelf and thought it had long since expired.
Actually, Helix is still very much alive! A new version 8 is in beta testing now. You can download a v8 beta client and use it to log into techdb.qsatoolworks.com, the support collection, and see it in action for yourself. Or, join the independent email discussion list at helix-l@gibhenry.com and see what people are asking and commenting.
I use Graphic Converter for:
rescaling/resizing images, cropping images, inverting/swapping colors, adding text or shapes, converting from/to JPG … etc
I have a simple Applescript that I saved as an app and keep in the Dock. Clicking on it activates the partial screen capture function of macOS where I can select an area of the screen. The app then opens GC and creates a new image with the clipboard. The Applescript is here:
http://mpainesyd.com/idisk/Public/snap2GC.scpt
It has worked well for more than a decade but with High Sierra or Mojave you need to allow the app to send keystrokes in System Preferences/Security & Privacy/Privacy/Automation (which is not easy to do!)