Just a small update, but it adds a few new things and fixes a few bugs too. Here's the list of changes:

• Added a reset option for curves, just right-click on a curve and you'll see it in the pop-up menu
• Added visibility toggle for emitters
• You can now  set the maximum amount of frames per row in the exported sprite sheet.  Originally sprite sheets would try and fit everything on one row until the texture hit a width of 16384, and then it would add a new row. 
• The current frame of animation can now be saved as an individual image. Just select "Current Frame" in the preview window after you've rendered an animation. The frame saved will be whatever is currently displayed, you can change this by stopping the animation and using the scrubbing control to flick through the frames.
• Resizing the window will now scale the GUI, not perfect but at least makes it somewhat usable on some lower resolutions
• Fixed bug where duration property wasn't working correctly
• Fixed bug with the spread angle cone flickering at some zoom levels