The UK’s coronavirus contact-tracing app is set to use a different model to the one proposed by Apple and Google, despite concerns raised about privacy and performance. From a report: The NHS says it has a way to make the software work “sufficiently well” on iPhones without users having to keep it active and on-screen. That limitation has posed problems for similar apps in other countries. Experts from GCHQ’s National Cyber Security Centre have aided the effort. NCSC indicated that its involvement has been limited to an advisory role. “Engineers have met several core challenges for the app to meet public health needs and support detection of contact events sufficiently well, including when the app is in the background, without excessively affecting battery life,” said a spokeswoman for NHSX, the health service’s digital innovation unit.