WhatsApp has been criticized for failing to help police following the revelation that Khalid Masood used the encrypted messaging service shortly before running down numerous people and stabbing a policeman to death in London last week.
A four-year-old boy in Croydon, south London, managed to call emergency services after finding his mother unconscious by using the Siri function on her smartphone.
Twitter is considering adding a paid membership option for business users in a bid to arrest slowing revenue growth and a sharp decline in its share price.
Although much was made about a new batch of iPhone and MacBook flaws disclosed by WikiLeaks on Thursday, Apple says the issues appear to all be old, since-fixed vulnerabilities.