xAP Flash can import these SWF Flash buttons and use them just like the internal ones but for speed reasons they're better if they are internal in the library so I welcome submissions of button designs that we can include.
If you use standard button images (gif, png, jpg etc) then currently only single or dual (on/off) state images are supported. We will eventually support 4 state which will include the 'unknown' and 'error' states and maybe more (blank - no icon - or dimmed for example).
If anyone want's one of the internal buttons as a Flash .SWA source example - to adapt and create new buttons / change colour etc - just holler. You will need Flash to edit it.