I carry a thumb drive with PortableApps loaded on it. It's full of all kinds of programs that I can use on any computer I come across. Familiarity is a huge plus here even though it's not the "Standard" software folks use. My thumbdrive has things like Firefox, Gimp, and a bunch of other programs that I use all the time.
It's be nice to be able to install Freestyle in a portable format so I can use it wherever I go. If I'm at the library, pop in my thumbdrive and run it right off there, no installation or anything. Just plug it in, load the program and start drawing.
Autodesk doesn't make any programs like this that I've seen. The closest is Sketchbook for the IPhone. Ohh, and there's Autodesk Fluid as a free IPhone App but, I haven't found a use for that one yet.
For the freestyle, I'm not talking about an App for the IPhone (although.... not a bad idea..). Hang on, why not talk about it as an App? I've always looked for a program I can pull up a drawing with to look at certain areas. Ever since I've carried my first handheld computer, HP something or another, I've always looked for a decent drawing viewer.. If it comes with the ability to make notes or redlines, that's major bonus points!!
Anyway, first make it portable, then make it an App..