How photo app Polarr topped the App Store the uncommon way

Conventional wisdom says that the technologies used to build websites are poorly adapted to the hotter and newer world of smartphone apps. But a photo-editing tool called Polarr may prove that thinking wrong.

Polarr broke from convention and utilized that Web technology as the foundation for its app, veering away from the idea of using code specifically intended to run on Apple's iOS software. Polarr now sits atop the App Store ranking for best new apps, and is downloaded by iPhone and iPad users 111,000 times a day.

"One year ago, we couldn't have done this," said Polarr Chief Executive Borui Wang said of the new Web abilities.

Polarr goes well beyond the filters that countless other photo-editing apps offer to tweak a picture's color and mood. With features matching many of those in Adobe Systems' Lightroom, which sets the standard for photo editing, Polarr lets you tweak color balance, adjust specific colors, fiddle with contrast using tone curves, and a lot more. You can adjust sliders in the iOS version by tilting your phone or tablet to one side or the other, though there's a 16-megapixel file size limit.

Its success is a rare testament of the effectiveness of Web technology on mobile -- an approach that Facebook Chief Executive Mark Zuckerberg called " one of the biggest mistakes if not the biggest strategic mistake that we made" in Facebook's initial foray into a mobile app.

You may not care about what makes your app tick -- so long as it ticks. But you should because ordinary folks can benefit when programmers can use Web technologies instead of writing apps that run natively on the dominant mobile operating systems: Apple's iOS and Google's Android.

That's because an app written using Web technologies can run on any mobile device, as well as on PCs. That means programmers can spend their efforts adding new features instead of recreating them for a new operating system. It also means that an app is also more likely to work for the millions of people using the BlackBerry 10 operating system, Firefox OS, Windows Phone or other second-tier operating systems.

The Web approach has proven its worth, said Redmonk analyst Stephen O'Grady, and he's optimistic Web apps will expand if not supplant native apps for Android and iOS.

"Virtually all of the things people said could not be done in a desktop browser are now done in a desktop browser, daily," O'Grady said. "I'm reasonably bullish over the longer term, given the history."

Key to expansion

That flexibility is key to Polarr's expansion plans. Its first product was a Web-based photo editor that 300,000 people a month use on personal computers. Over the course of two months this year, Polarr re-crafted its user interface to work on iOS devices and released version 1.0 on June 25. Now the Android version is in the works, scheduled to arrive at the end of July if all goes well.

"For Android it's going to be even faster," Wang said. "Android has pretty much the exact same Web interface."

Polarr, a Cupertino, Calif.-based startup with seven employees, can't afford to squander resources. It raised $1 million in venture funding from Pejman Mar Ventures and Stanford StartX, Wang revealed, and its ambition is to be a profitable company, not a "lifestyle business" that merely supplements his income. The company plans to raise another round of funding later this year, too, so expanding to new operating systems is crucial for showing growth.

Polarr is free, but the company makes money today through in-app purchases that unlock higher-end features aimed at people who want more than Instagram but aren't willing to pay $10 a month for an Adobe Lightroom subscription. The company doesn't plan to expand into online services, a move that would put it in competition with companies like Google and Flickr, but it does plan to add advanced new editing technology, Wang said. "The hope is that we do some sort of more intelligent services. I have an artificial intelligence background," Wang said.

The Web offers a way for programmers to reach a lot of devices, but it's far from universal. On Android, the key limit is older devices with underpowered graphics hardware.

That makes testing important -- but with so many devices, also difficult. Polarr programmers took an unusual approach to the challenge. First, they wrote a special-purpose testing website. Then they sent staff to Best Buy and Verizon stores to load the test site with a multitude of phone Web browsers. It was awkward -- especially for actual customers waiting in line to try the phones -- but it was enough for Polarr to figure out it could only support its software on the latest version of Android, Lollipop.

Welcome WebGL

What changed over the past year to make a mobile version of Polarr possible? In a word, WebGL.

This technology, developed initially by Firefox maker Mozilla then picked up by Google's Chrome team, lets a Web app tap directly into the power of a computing device's graphics processor. That means higher performance and lower battery consumption for the kinds of tasks an image-editing program does. When Apple released iOS 8 in 2014, it added WebGL support so third-party software like Polarr could recycle its existing Web-based software for iPhones, too.

Writing software using Web technologies isn't always easy, though, Wang said. Programmers must choose the best of an immense range of prewritten software, for example, a more daunting prospect than the more tightly controlled programming environments Apple and Google offer to build native apps.

Another challenge: although it's easy to get started with the Web's programming language, JavaScript, it's difficult for building large-scale apps. And JavaScript-based apps use more memory than native apps, Wang said.

One new technology from the browser teams at Mozilla, Google and Microsoft could help reduce memory usage and cut down on the app launch time. It's called WebAssembly, and it's designed to open Web apps up to more languages than just JavaScript. Greg Pollack, founder and CEO of online learning site Code School, predicts WebAssembly will dramatically expand the abilities of Web apps by offering new horsepower.

"Right now in order to do video editing effectively you have to download a native application" because JavaScript isn't up to the task, he said. "With WebAssembly the browser performance of a video editing application is going to get a major speed boost."

Not even fans like Polarr expect Web-based apps to push aside all native apps. But as technology continues to mature, it's got a fighting chance to win over programmers.