At the Symbian Exchange & Exposition (SEE) taking place in London this week, mobile OS developer the Symbian Foundation officially launched its application publishing platform – Horizon.

Symbian developers can now sign up to Horizon and have their apps listed in the Symbian Horizon Directory, processed through Symbian Signed, and published to the organisation’s app store partners.

The Foundation said that there are now a total of five app stores supporting Horizon. Along with the initial stores – the Ovi Store by Nokia, Samsung Applications Store and AT&T’s MEdia Mall, new additions include China Mobile’s Mobile Market, and Sony Ericsson’s PlayNow arena.

Laura Merling, acting head of developer programmes at the Foundation, recently told telecoms.com, “ If you think about a developer, the market for Symbian is pretty fragmented. There are 25 different stores that you might deploy your app into to get distribution. With the Apple iPhone there’s just one store. So how do you get enough apps in the store if you’re the store owner—and, if you’re the developer, do you want to choose one store over another? You want the broadest distribution, so you want to be in all of them. But there are time and money costs associated with that. So our goal with the Horizon platform is an app publishing platform. The goal is to minimise the cost to the developer for getting distribution.”

According to the Foundation, approximate figures suggest Horizon can reduce the cost of publishing apps by about 75 per cent, assuming developers want to push their work to 6 stores.

But since the initial launch plans were announced in July, Symbian said it has processed 50 applications. This perhaps highlights the bottleneck problem likely to arise from the application inspection process as app stores rise in popularity. Screening each and every application to be made available for a certain platform is a timely process as well as an expensive one – more so for fragmented platforms like Symbian and Linux – and for developers who depend on getting their wares into the market as soon as they’re released time is indeed of the essence.

And over the long term, Symbian acknowledges that running Horizon will not be cheap so the Foundation has announced plans to open source the development of the business model, in line with its initiative of embracing the outsourcing model wholeheartedly. Answers on a postcard please.