I'm getting overwhelmed by all these nifty browser based prototyping tools coming out. Very cool stuff, but it seems like the market is starting to get a little saturated
I'd actually prefer a desktop app that does some of these things, considering I don't want to install Air for Balsamiq, and don't really want to do all my work in a browser, on a service that could disappear at any moment.
Sadly, I'm not the person with the expertise to do it.
What's wrong with Air? Balsamiq works quite well for me, don't notice any problems caused by Air.
It's slow, non-native, and resultantly slightly obtuse and frustrating to use.
Non-native, true. But slow? Balsamiq on my PC is nothing but snappy. You should consider sending a support request in case there is a bug in Balsamiq(or Air?) with your OS/pc configuration.
There are a number of desktop wireframing applications - Omnigraffle, Axure, Visio come to mind.
I swear by FlairBuilder. We've built complex sites using this for prototyping and the learning curve isn't high at all.
There's a tool called Pencil[1] that runs on the browser, but works offline. Haven't explored a lot, but does simple tasks well.