Yandex is the dominant search engine in Russia, besting even Google, and now it's stepping further into the mobile space with the acquisition of developer SPB Software. The move is centered around the popular SPB Shell 3D skin for Android, Symbian, and Windows Mobile, with Yandex planning on using the UI "to integrate Yandex's cloud services and technologies." The company recently partnered with Microsoft, Nokia, HTC, and Samsung to make it the default search engine on Windows Phone 7 devices shipping in Russia, and with Yandex pledging to use the acquisition to "provide easy access to the company's services on a broad number of mobile devices," we wouldn't be surprised to see SPB Shell 3D showing up in one form or another on WP7 phones either. There's no word yet on whether the skin will continue to be developed as a standalone product, or if it will become a Yandex exclusive. Take a look at the video below to see it in action.