As digital comics have risen to become a $25 million a year business, even more specialized apps for different comics genres are emerging. Clearly, there’s an audience: ComiXology has become the #3 grossing app for iPad for all of 2012 with some 25 million comics downloaded from their various apps this year.

While ComiXology has spotlighted mostly well-known publishers such as Marvel, DC and Image, two new ventures feature more offbeat fare. San Francisco-based start-up Emanata is an iOS app that distributes indie comics with an interface part ComiXology, part Deviant Art. Comic Chameleon is a more grassroots venture by cartoonist Bernie Hou to deliver popular web comics such as XKCD to mobiles devices.

Emanata launched in summer as an “artist spotlight” app and added paid downloadable content in October. It started out as a publishing platform, says founder George Chen, who has stints at AdMob, Google and Churn Labs in his past. As they were looking for test material, the Emanata team came upon a treasure trove of “very good comic book artists and designers who like to tell stories.” Chen realized that many of the artists may not have owned an iPad but could benefit from having exposure on the platform.

The platform offers conversion to the mobile platform free to artists who want to be on the app, and splits revenue 50/50 with creators once Apple’s 30% cut is taken. However, as an incentive for artists to sign up, Emanata offers them the full 70% of revenue for the first month they’re on the platform. Stories offered range from five page shorts to full-length graphic novels are priced accordingly.

Artists available through Emanata thus far include Malachi Ward and Jess Smart Smiley; checking the app page shows a revolving cast of bestselling titles. For some creators, Emanata is a revenue stream, says Chen, but others can offer their books for free to get wider exposure on the mobile platform.

While sales are still modest, Ward said he’s glad he’s on the platform. “I’ve definitely sold some comics through it.”

Chen notes that even given indie cartoonists preference for print, many are savvy users of social media and create their comics digitally already. He hopes Emanata will also grow into a way for readers to discover and track favorite artists. “We’re building a groundwork. When a user finds a new artist they can follow them within the app and see what new comics they have, as with Facebook or Twitter.”

Meanwhile Comic Chameleon offers a concise way to follow the dizzying world of web comics: mega-popular strips XKCD, Girls with Slingshots, Nedroid and Dinosaur Comics will be available as a feed on the app, and panel flow will be optimized for even the small iPhone screens. According to Hou, the app was born of his own frustration. "As an iPhone haver and a webcomics lover, I naturally wanted a way to read web comics on my iPhone that was better than going to each of their websites and then awkwardly pinching and panning and zooming around."

Hou launched the venture with a friend who develops apps. They hope to submit to Apple in January, and an Android version is also in the works. Comic Chameleon offers an alternative so so-called "scraper" sites that aggregate web comics without the creators participation—Hou is already known in the web comic community, making signing up strips easier. Once the app launches, it will operate on a shared revenue model, with advertising money going mostly to the creators. "A lot of people have told us already that they'd be willing to pay for Comic Chameleon," says Hou, but "we feel strongly that the app should be free, in order to help our artists reach the most readers."

A preview video of the app can be viewed on YouTube.