Version Reviewed: 1.2
iPhone Integration [rating:4]
User Interface [rating:4]
Re-use / Replay Value [rating:4]
Instaviz is touted as a graph sketching tool. It supports multi-touch features to draw shapes such as circles, ovals, squares, and triangles, label each, and then connect them to one another. Not unlike Microsoft's Visio, you can use Instaviz to visualize complex interrelated concepts. You can then export the files you create to a number of different file servers, including MobileMe.
Instaviz is based on Graphviz, an open source visualization tool for the Mac, Windows, and Linux. Instaviz can connect to and export its files to iDisk, box.net, and WebDAV. While iDisk is part of Apple's MobileMe, box.net is a subscription based online file system that offers several free and paid plans.
WebDav "is a set of extensions to the HTTP protocol which allows users to collaboratively edit and manage files on remote web servers." That quote is from the WebDav.org web site, and should give you some indication of the fact that this is not a software service, but is instead something users can download and install on their own web servers.
Instaviz has a pretty robust set of tools. While it is very light on documentation (the author's web site doesn't really offer anything that isn't already available in-game, and both are very sparse), if you are familiar with Visio or other visualization tools, it's pretty intuitive. You use your finger to draw shapes, including circles, ovals, squares, and triangles, and then draw lines between the shapes to connect them.
The app automatically rearranges the shapes as you connect them. You can double-tap shapes to get to options to edit their text, change fonts and colors, as well as many other attributes. Instaviz has a wide variety of options and uses multi-touch to zoom in and out. Once you export the files to one of the previously mentioned file services, you can then download them to your PC and view or print them in Graphviz.
As mentioned, documentation is sparse for Instaviz. If you have experience with visualization or graph sketching tools, this shouldn't be a problem. For someone who thinks they need something like this but has little experience, though, you will likely have to find online resources or a good book on the subject. Other than that, my biggest complaint is that it doesn't appear to be compatible with Microsoft Visio or any other similar tools.
Since Instaviz is expensive compared to many iPhone apps, and its appeal is probably limited to software designers and other technical people who are used to similar visualization tools, it's definitely not for everybody. It does offer a pretty robust set of tools, though, and it's all integrated fairly well into the iPhone, with great support for multi-touch. If you need something like this, you will likely find it good enough for a little on-the-go graph sketching.