A report looking at health apps, for diabetes, asthma and the NHS' health apps library, has found problems with all of them.
The report, ‘Trust but verify' - five approaches to ensure safe medical apps, by Paul Wicks and Emil Chiauzzi, both PhDs employed by PatientsLikeMe, was published in the journal BMC medicine.
The report found that apps designed to help patients calculate their insulin lacked ways to validate user input and made inappropriate recommendations of dosage.
Asthma apps reviewed saw that there were similar problems with peak flow calculators.
The report recommends boosting app literacy among consumers to ensure they are fully aware, having an app safety consortium, enforcing transparency, having an active medical review of apps or government regulation to tackle the problem.
The report said: "In order for medical apps to evolve, improved oversight and continuous quality review is required.
"Centralized oversight by regulatory bodies has the advantage of regulatory expertise and powers to sanction.
"However, these regulatory bodies are too under-resourced to wade through the sheer volume of apps and there appears to be little appetite to get involved."
The report added: "In the UK, the NHS Health Apps Library requires developers to complete a structured series of questions about security, quality, and privacy to be reviewed by an internal team. However, in the third linked study by Huckvale et al.
"The authors found a number of flaws regarding privacy in accredited apps.
"Moreover, most patients access apps through native stores rather than accredited portals, further highlighting the importance of wariness when it comes to security and privacy issues.
"In an accredited environment, the speed and revision of review is an important factor when review processes take months or years, while apps can be updated in a matter of weeks and hardware changes regularly."