Users of Android devices have reportedly been among the worst hit.
A follow-up message will now be sent to reassure those worried by alerts. But “ghost notifications” cannot be stopped.
The app needs a minimum of seven million people to be using it for it to be effective.
App launched in England and Wales on Thursday, after months of delay
The NHS Covid-19 app will be released this week but questions remain unanswered about how it has performed during testing.
Virtual-reality developers in California have created a character whose job it is to get fired every day. Barry is part of a workplace training tool to help management and employees deal with difficult situations.
The Pokemon Company has announced Pokemon Sleep, a new app in development which promises to “turn sleeping into entertainment”. The app will track a user’s sleeping patterns and use them to influence gameplay, building on the work of walking-based Pokemon Go. Pokemon Sleep will be available in 2020.
WhatsApp has fixed a security glitch after concerns hackers could inject surveillance software on to phones via the call function. There were fears it targeted human rights campaigners. The app said the breach hit only a “select number of users” and released a software update on 13 May.
It follows an overnight security breach.
A "research" app, which has been running since 2016, was deleted hours after an exposé.