Open Air Publishing, digital publisher of interactive how-to books for the iPad and iPhone, has closed an $800,000 seed round of financing, including investments from SV Angel, Charles River Ventures, and 500 Startups.

Since its launch in May 2011, the company has released four digital books for iPad. The funding announcement coincides with the release of all four titles for the iPhone: Master Your DSLR Camera, Speakeasy Cocktails, The Better Bacon Book, and Holiday Recipes & Party Planning Guide by FOOD52. Its apps are priced from $4.99 to $9.99.

“The iOS platform invites a reinvention of the e-book, and Open Air Publishing is building tools and processes to define the publishing/studio hybrid model needed to make true e-book content,” said Jon Feldman, founder & CEO of Open Air Publishing. “We’re excited to have this great group of investors and advisors on board as we hit our next phase of growth. We’ve doubled the team to six and plan to have nine new titles out by the end of this year.”

Open Air's books are powered using Inkling’s digital publishing platform, Habitat.