One of the iPad's best-loved apps, Paper, is becoming that little bit more attractive today with the announcement that its full set of drawing tools will be bundled into the free app. Previously costing $0.99 each as in-app purchases, the Sketch, Outline, Write, Color, and Mixer tools are now available to all comers as soon as they download Paper. They add a watercolor paintbrush, a sketching pencil, a marker, and a ballpoint pen to the app's default fountain pen, while also allowing users to mix colors in a simulated palette. FiftyThree, the company that began its life with Paper in the spring of 2012, now has a pair of related projects that help explain how it can afford to make its software completely free. I spoke with CEO Georg Petschnigg ahead of today's news, and he laid out the thinking behind his company's choice to forego in-app revenue in search of a bigger prize. The poetic reason has to do with the Mix collaboration and sharing service that FiftyThree introduced in September of last year. In just a few months, it has brought together more than 800,000 people across 192 countries, amplifying the popularity of the original Paper app, which has to date been downloaded 13 million times. Petschnigg is delighted with the response to Mix and wants to push its adoption further by making it more inclusive. Giving everyone access to the same set of tools is a step toward that, though it's all driving toward an economic goal at the end as well. Paper is already proving popular in education, and Petschnigg says that his company's "long-term objective will be to open that up to businesses and schools," with licensing from those institutions funding further development of Paper and Mix. The more pragmatic angle to FiftyThree's present decision is that selling Pencils — the Bluetooth stylus that marks the company's first foray into making hardware — is proving a highly successful venture. "Pencil has been doing phenomenally well," says Petschnigg, and now ranks as Amazon's best-selling digital stylus. A new Gold Pencil has started shipping this week, costing $59.95 like the Walnut option already available (there's also a more basic Graphite Pencil for $49.95), and Apple Stores are rolling out all three of the Paper styli around the world. Buyers of the Pencil already get the full suite of Paper tools for free, but the goal today is to stimulate more people to consider buying a Pencil once they see how fun and useful those tools can be. Georg Petschnigg and company "anticipate this will also lead to an increase in Pencil sales," stimulating what appears to be the most profitable part of the business right now. FiftyThree isn't ruling out the option of introducing new paid tools and features as it continues build out Paper, saying that "the in-app purchase model has worked really well." For now, though, the company's focus is on attracting more users to Pencil and Mix, with Paper serving as the application showcasing their appeal.