Wow! I just fiddled with it a little bit and it seems very useful for when I finally decide to tackle the small problems[1] that I encounter with the SVG's that I use. The UI is easy to understand and it gives clear feedback on changes. I definitely bookmarked this.

[1] The problems that I had with some SVG's is that they seemed to stretch the page wide while loading (in a flash) and then finally settling on their intended size after a split second. I remember that I searched for solutions and fiddled with viewbox, widht and height, but to no avail (they were in the hundreds of pixels). What can I do to mitigate this initial 'stretch'?