Deleting Email

Stewart Butterfield of Slack tells us why he thinks email at work is on the way out. Eben Upton, creator of the Raspberry Pi educational computer reveals a new direction for the project into industry. And Mike Cassidy, Vice President of Google's Project Loon, a plan to provide the internet to remote places using balloons in the stratosphere, tells us how the company is edging towards creating a ring of such balloons around the world.

Presented by Rory Cellan-Jones, with special guest Blathnaid Healy, UK Editor of Mashable, and Chris Foxx from the BBC Online tech desk. (Picture: Young office workers using social media, Credit: Thinkstock).