The Irish company behind Ireland's Covid-19 tracker app has launched a similar service in the US state of Delaware.

The NearForm app is now being used in Ireland, Northern Ireland, Gibraltar, Scotland and will be launched in more US states over the coming weeks.

The governor of Delaware, John Carney, announced today that the new "COVID Alert DE" app will use Bluetooth technology to securely and anonymously alert users who have been in close contact with someone who has tested positive for Covid-19.

The app will allow for interoperability and exposure notifications across state lines in US states that also have exposure notification apps and use the same Bluetooth technology.

Cian Ó Maidín, the CEO of NearForm, said the state of Delaware was using technology that has been peer-reviewed and rolled out successfully in Ireland and parts of the UK.

"The COVID Alert DE mobile app puts power in citizens’ hands to protect each other in the fight against Covid-19," Mr O Maidín said.

"The open source technology was built with privacy and data protection at its core. The app exchanges regularly-changing anonymous Bluetooth ID, to break transmission chains," he added.