Highlights from Google I/O 2015

Google is holding its annual I/O developers conference in San Francisco.

At the opening event, the firm showed off forthcoming features in the next version of its Android mobile operating system - including revised privacy settings and a new digital wallet scheme called Android Pay - as well as new version of its Cardboard virtual reality headset.

It also fired a shot across the bows of Apple by releasing a cloud-based photo and video organiser app that offers "unlimited" online storage for free.

The BBC's North America Technology correspondent Richard Taylor reports.