LIVE FROM OPEN MOBILE SUMMIT LONDON 2012: Browser fragmentation, discovery and development costs are all potential challenges when developing HTML5-based web apps, industry experts have said.

Speaking in a panel discussion at the Open Mobile Summit in London, YouTube head of mobile Andrey Doronichev said a problem his team encountered when first developing HTML5 technology was the different way in which mobile browsers dealt with it. “Browser fragmentation is a problem,” he observed.

After building a well-received HTML5 app for the iPhone 3G, Doronichev said the YouTube team then found that it didn’t work properly with an upgraded version of Apple’s Safari browser seen in the next model.

New York Times CIO Marc Frons agreed that browser fragmentation is an issue that his team has also encountered – but learned to deal with. “It’s a write once, debug everywhere approach,” he said.

Doronichev said YouTube soon realised that it needed to work with browser companies to overcome the issue. “Collaboration with browser manufacturers was key to enabling our HTML5 platforms,” he continued.

The YouTube executive also said app discovery is a challenge with HTML5 apps as they can exist outside the traditional app store environment, meaning people don’t always know where they are. “There is no single place to go to get HTML5 apps.”

Despite press coverage and marketing campaigns, one version of YouTube’s HTML5 app took much longer than expected to generate significant downloads and revenue, as people weren’t aware of it.

FT.com managing director Rob Grimshaw acknowledged that there were concerns about discoverability when his company decided to shift 1.3 million customers from its iOS app – which it was closing – to an HTML5 version.

“We found that we can overcome that by thinking about the user journey carefully,” he said, explaining that the company simply informed users that there was a new app available and where they could access it. More than 90 percent of its iOS users moved to the web app.

Grimshaw added that the web is in some ways better than app stores for finding apps, due to more effective search technology.

Jiri Kupiainen, founder and CEO of Disney-owned developer Rocket Pack, agreed that the fact the apps are web-based means they are often easier to find than in app stores. “With HTML5, we have the broadest amounts of possibility,” he said.

The final issue discussed by the panel was the relatively high cost and scarcity of developers well versed in HTML5. “Developers are definitely getting more expensive,” the New York Times’ Frons said.

FT.com’s Grimshaw agreed that with HTML5 being a relatively new area of development, costs are relatively high. But he added that this will change over time.