Google has announced a new version of its cheap and cheerful virtual reality viewer Cardboard - and it supports iPhone for the first time, Digital Spy reports.

As the name indicates, the accessory is still made from cardboard and requires some minor origami to put together, but it now takes shape after just three folds.

Cardboard is now compatible with phones of up to six inches, and Google has released its software development kit to iOS programmers so they can make their apps Cardboard optimised.

The original Cardboard shipped more than one million units and there are hundreds of compatible apps for it, but that number will increase following the launch of Google's Jump system.

Jump is a 360-degree camera rig kit developed with GoPro that enables filmmakers to record virtual reality video, and YouTube will be hosting these clips.

Google is yet to announce a consumer release date for the new Cardboard viewer, but handed them out to developers at its I/O conference.