Google's an annual developers conference kicks off on Thursday in San Francisco, and Google's executives are expected to focus on Google Cardboard gadget and a new Andoid version. Google cardboard is a cheap gadget that turns smartphones into virtual-reality goggles. Google is expected to spend time at the conference talking about a cardboard in order to urge developers to create more software and features for cardboard-equipped smartphones.

The $25 Google device has a slot for Android-based smartphones, which are turned into virtual-reality displays using specialized applications. Users can then look through lenses on the boxes to experience the digital environment.

Google has struggled to get some of its devices adopted more widely. Earlier this year, the company scaled back plans to introduce Google Glass, its Web-connected-eyewear. The company also struggled to get more people to use Google TV.

A new version of Google’s Android mobile software, as well as updates for Google's efforts around other platforms, including television, Web-connected devices and automobiles, are also expected to be hot topics during I/O.