Favicon Generator. For real. [↗]
With so many platforms and icons, it’s hard to know exactly what you should do. What are the dimensions of favicon.ico? How many Touch icons do I need? RealFaviconGenerator did the reseach and testing for you.
This is pretty nifty. I was thinking of creating a web version of my Faviconator Ubuntu app, but after looking at this, I’m not sure I’ll bother.