coronavirus cases, contact tracing is quickly becoming the backbone of control and containment.A federally backed tracing app is on the horizon, and experts have said that about a 60 per cent participation rate is needed in order for it to be truly helpful for tracking the spread of the virus.Since the method is reliant on owning a smartphone, it might miss the mark with some demographics, experts say.“That’s the tricky part here — you need an app that is endorsed but also adopted,” said Emily Seto, an engineer and health technology specialist at the Centre for Global eHealth Innovation at the University of Toronto.