The next release will include custom icons. I'd like your help with beta-testing this feature.
The way this feature works is you place SVG images in any folder under assets that starts or ends with icons. For example both assets/AndroidIcons and assets/iPhone Icons work. Another option is to prefix the icon name with icon (e.g. icon-refresh.svg). Note that the final icon list is flat so pay attention not to repeat names across folders.
Get the development version and help me with testing. Let me know how this feature works for you. Thanks!