Period tracking app Flo is developing a new feature called "anonymous mode" that will allow users to remove their name, email address, and technical identifiers from their profile. Period trackers have faced scrutiny over privacy concerns in the wake of the Supreme Court's decision to overturn Roe v. Wade.

While the new feature had already been planned, the Supreme Court decision accelerated its development, according to a press release.

"Flo will always stand up for the health of women, and this includes providing our users with full control over their data," said Susanne Schumacher, the data protection officer for Flo, said in a release sent to NPR. "Flo will never share or sell user data, and only collects data when we have a legal basis to do so and when our users have given their informed consent. Any data we do collect is fully encrypted, and this will never change."

Flo emailed users of the app on June 29 that this feature will be available in the coming weeks. On social media, there have been many calls to delete these apps. The company also teased the release of the new feature on Twitter last Friday.

In the email, signed by the data protection officer, the company said that once a user activates the anonymous mode, an account would be stripped of personal identifiers. If an official request comes to connect an account with a certain individual, Flo would no longer be able to do so.

"If Flo were to receive an official request to identify a user by name or email, Anonymous Mode would prevent us from being able to connect data to an individual, meaning we wouldn't be able to satisfy the request," Schumacher said in an email to users.

Activating anynomous mode however may limit personalization features the app offers and users will be unable to recover their data if a device is lost, stolen or changed Flo said.

The menstrual app also told users they can request to have their information deleted by emailing customer support.

Flo has amassed more than 48 million active users and is one of the biggest health apps on the market. In the past, the company's use of user data has warranted federal investigation. In 2021, Flo reached a settlement with the Federal Trade Commission over concerns the company misled users with their privacy policy.

Experts say health privacy goes beyond health apps. Search histories and location data are other areas where technological information can be exploited says Lydia X. Z. Brown, a policy counsel with the Privacy and Data Project at the Center for Democracy and Technology.

The choice to keep period trackers or delete them depends on an individual's circumstances. However, those in states where abortion is criminalized may want to take extra precautions advises Andrea Ford, a health research fellow at the University of Edinburgh.

"If I lived in a state where abortion was actively being criminalized, I would not use a period tracker — that's for sure," Ford previously told NPR.