France has launched a new version of its troubled Covid-tracing app to a rough start plagued by server issues.
Renamed as "TousAntiCovid" - Everyone Against Covid - it is an update to the StopCovid app, which was never widely adopted among the population.
The new version was downloaded more than 500,000 times in the hours following its launch.
But that surge in popularity led to stability issues, with many unable to activate the app.
Only about 2.
5 million people have downloaded the app since its initial launch in June - with even Prime Minister Jean Castex admitting he had not done so.
The relative boom in download numbers remains smaller than other countries' apps.
The NHS Covid-19 app for England and Wales, for example, was downloaded more than one million times in its first 24 hours.
The new version of the app launched as France extended its overnight curfews, with Mr Castex declaring that "the second wave is now under way".
The country announced 41,622 new cases - a national record since the pandemic began.
Teething troubles TousAntiCovid was revealed in a surprise announcement by Mr Castex on morning television, 10 days before its release.
It was made available for download on Thursday evening and topped the national Apple app store chart for free apps - but quickly suffered from teething issues.
French users posting on social media reported not being able to access the app, being stuck on its home page, missing text or text in English rather than French.
Others were unable to activate the app, getting error messages.
France's digital minister Cedric O told television station France 2 on Friday morning that the issues were caused by a flood of too many people using the system at once - but claimed the problem had been fixed overnight.
Health officials are characterising the rebranded app as an "enriched" version of the original StopCovid app.
The update has new visuals, an "information centre" with statistics news about local measures, and integration with services such as travel certificates used to move around areas affected by curfews.
French officials are planning to add a QR-scanning system for restaurants and other venues, similar to the system used by the NHS app and others, to help keep a record for contact tracing.
French Broadcaster BFMTV said that including the people who had installed it previously, there were now more than 3.
3 million people who had downloaded the app.
That still lags far behind other nations - the England and Wales app has been downloaded more than 18 million times, while Germany's is estimated to have accumulated more than 19 million.
France's app is also different from that used by some of its neighbours.
It uses a "centralised" system that sends the data from a phone to government computers to do the contact-matching.
That option was also once considered by the UK because it is thought to be helpful to epidemiologists analysing the data.
However, the more widely-used alternative - doing the matching on phones - is said to be more privacy-focused, which supporters believe could encourage more people to use it.