Click looks at the digital tools that are being used to help authenticate works of art - as well as spot the fakes and forgeries. We also talk to the estate of David Bowie who tell us about a project the singer was working on before his death that would allow artists to authenticate digital art works. We go to the Google developer conference to find out what updates and new tech the company is planning and look at some of the tech that is helping people better deal with mental health issues.