The UK could either “adapt” its coronavirus contact-tracing app or ditch it and “move to a different model”, after piloting it in the Isle of Wight and learning lessons from other countries. About 40,000 people in the Isle of Wight have been trialling the app, designed by an arm of the NHS, which alerts users if they have been near to a suspected case of coronavirus. However, there has been intense speculation the UK could have to change its app to a “decentralised” model favoured by Apple and Google, which stores data about movements on a user’s phone rather than centrally in an anonymised form with the government. Amid reports of teething problems with the app, Robert Jenrick, the communities secretary, suggested changes could be on the way. “We are learning lessons from other apps and if we need to change our app we will do. That’s the point of piloting it before we roll it out nationally,” he told the BBC’s Andrew Marr Show. He denied the idea that there was already a second app being designed but indicated the government could change tack in future. “As far as I’m aware we’re not developing a second app but we are paying attention to the other apps that exist elsewhere in the world,” he told Marr. “And if we need to adapt our app or move to a different model, obviously we will do.” MPs and privacy campaigners have repeatedly warned the UK will be an outlier if it insists on using its own centralised app rather than relying on Google and Apple’s technology, claiming the lack of privacy and data protections could mean that the app would be illegal. With growing questions over that approach, it emerged last week that the Swiss-based consultancy Zühlke Engineering has been hired to undertake a two-week “technical spike” to investigate implementing Apple and Google’s system “within the existing proximity mobile application and platform”. Zühlke has already been working on the contact-tracing app since March, documents published this week show, but a new outsourcing contract, first reported by the Financial Times and uncovered by public sector analysts Tussell, shows the government is seriously considering changing how the application works to overcome problems with its initial approach. Last week, the prime minister’s official spokesman left open the possibility that a change could be made, telling reporters: “We’ve set out our plans for a centralised model and that’s what we are taking forwards but we will keep all options under review to make sure the app is as effective as possible.” The centralised model brings advantages in terms of useful insights into the spread of the disease, but also imposes technical limitations that the government has not been able to fully overcome. The Guardian reported on Wednesday that the app relies on a form of “Android herd immunity”, facing connectivity issues in situations where there are not enough users of Google’s smartphone operating system. A switch to the decentralised approach created by Apple and Google themselves would solve these connectivity issues, but limit the visibility the NHS has on the wider spread of the virus.