I love Artrage and I was thinking it would be quite cool if we could have commands that would make it easy for those using tablet without keyboards.

-Zoom, pan and rotate should have an option to behave that he same way it works with the buttons over reference pictures, "on press" and then revert to the previous tool on release.

-A Color picker that would revert to the previous tool after the selection.

-A button somewhere to Flip horizontally and hold till depressed.