Comment by petedoyle

This is huge. A limiting factor has been iOS not being able to (on purpose, for privacy, and battery life) do BLE scanning (edit: or advertising, thanks Slartie) in the background. I imagine this will enable that for specific apps, and I have high confidence privacy will be well-implemented by Apple's involvement (edit: see tastroder's comment for technical docs). Having a single, well-designed spec for Bluetooth advertisement will prevent a world where there are different contact tracing apps, none of which can see each other. Doing this at the platform level will enable enough density of installs to make this effective at scale.