Three developers have released software that allows Windows Phone 7 users to "sideload" applications onto their phones, giving access to applications that have not been approved by Microsoft.
Developers of ChevronWP7 say that their intention is to let people build their own applications and use them on the phones. Because Microsoft does not approve of the tool, using it is risky, but corporate users could be among those most interested in it.
Microsoft vets applications before loading them into its Marketplace app store, similar to Apple's App Store procedure but unlike Android's Market, which is totally open. Microsoft says the policy ensures people download only secure applications that are free of malware.
But the developers of ChevronWP7 argue there are good reasons for wanting to use unapproved applications. "Unlocking allows the sideloading of experimental applications that otherwise can't be published to the Marketplace, such as those which access private or native APIs," they wrote in a blog post. Sideloading refers to transferring applications to a phone, typically from a PC.
Corporate users often want to use applications that aren't available in the public markets. With previous mobile-phone software from Microsoft and some other mobile platforms like the iPhone, companies can develop and load applications onto employee phones without needing to post the application in the public application store. With WP7, however, that's not possible. Microsoft requires companies to upload such applications to the public Marketplace.
"So either you give everyone in the world access to your proprietary app - or you go without," wrote mobile enthusiast Terence Eden in a comment on a blog post about ChevronWP7. "With this tool, a company can unlock the phones they've purchased, install their own application on them, then distribute to the field."
However, using a tool like ChevronWP7 could also create problems for corporate users. "As soon as [phones are] jailbroken, the likelihood of malware is much higher," said Tim Weingarten, CEO with Visage Mobile, a company that offers software for managing smartphones. "Corporations on one hand want the flexibility to have their own internal app stores where employees can download apps, but they want them to be as secure as possible."
He expects that as WP7 evolves, Microsoft will support such internal app stores.
Microsoft said it discourages people from using ChevronWP7. "We anticipated that people would attempt to unlock the phones and explore the underlying operating system. Attempting to unlock a device could void the warranty, disable phone functionality, interrupt access to Windows Phone 7 services or render the phone permanently unusable. In addition, only apps and games acquired through Marketplace are certified for quality, performance, content and user safety," Microsoft said in a statement.
ChevronWP7's developers say that they haven't modified the operating system at all. ChevronWP7 simply enables the same functionality that Microsoft offers to registered developers, they say. WP7 developers who pay $99 to register can load apps onto their phones for testing.
"I must emphasise the ability to sideload and run unpublished applications is a supported functionality of all Windows Phone 7 devices," Long Zheng, one of ChevronWP7's developers, wrote in a blog post. "Although not enabled by default, it's a behavior embedded into the design of the operating system itself. That's all ChevronWP7 does."