37Signals is well-known as the developer of some powerful collaboration tools for the Web like Campfire and Basecamp. It's obvious that the employees of the company know how to use a chalkboard to sketch out flow charts, scrawl UI mockups, and so on.
In fact, the four team rooms in the company's new offices have corkboard walls and large chalkboards to facilitate brainstorming, and 37Signals employees wondered if they could take those chalkboards with them everywhere. The result? Chalk, a free iPad-only web app.
To use the free Web app, just use
