The Saudi government app Absher is mostly a way for people to pay traffic fines and complete other administrative tasks electronically. But one feature isn’t sitting well with civil-rights advocates: the ability for men to grant or deny a woman permission to travel.

Regardless of their age, women in Saudi Arabia must have the consent of a male relative to obtain a passport, travel or marry. In the past, a travel permit was a paper document issued by the Interior Ministry and signed by a male relative. The Absher app replaces the need for a paper document.

The app is merely implementing existing laws, and removing it would not change or remove the guardianship rules in place. Nonetheless, the feature has sparked calls for leading tech companies to block access through their app stores.

“The ingenuity of American technology companies should not be perverted to violate the human rights of Saudi women,” U.S. Rep. Jackie Speier, a California Democrat, wrote in a letter to Apple and Google.

The app is merely implementing existing laws, and removing it would not change or remove the guardianship rules in place.

According to Speier’s office, Google won’t remove the app because it doesn’t consider it a violation of Google’s terms of service, while Apple is still investigating.

Google and Apple did not respond to requests for comment.

Although the app has been around for years, it has only recently gotten the attention of human-rights and other critics.

Some civil-rights advocates acknowledge that the ability for guardians to control travel permissions exist regardless of the app. But they complain that U.S. companies are enabling that practice by allowing the app.

“These companies don’t have to support this,” said Jillian York, director for international freedom of expression at the Electronic Frontier Foundation. “They’re making the choice.”

Sen. Ron Wyden, an Oregon Democrat, wrote Apple and Google to criticize that they “are making it easier for Saudi men to control their family members from the convenience of their smartphones and restrict their movement.”

The app includes a setting where Saudi men can grant or deny their spouses, daughters and minor sons the ability to travel abroad. Through an integrated system, immigration officials at the airport can see the status of a woman’s travel permit by scanning her passport details. According to published reports, the government’s system can also send text messages when dependents exit and enter the country, though the app itself doesn’t appear to track women using the phone’s location services.

Some Saudi citizens have pushed back against calls for the app’s removal. Khawla Al-Kuraya, a female professor in Riyadh, Saudi Arabia, wrote in a Bloomberg opinion piece that the app makes travel easier to enable by cutting out long lines and paperwork.

The Saudi Interior Ministry said the app is “an essential and direct means” for Saudis to access government services anytime, anywhere. The ministry also condemned what is said was a “systematic campaign aimed at questioning the purpose of Absher services.”

Apple’s app guidelines seem to give the company latitude in what apps are considered unacceptable, including those that have “content that is offensive, insensitive, upsetting, intended to disgust or in exceptionally poor taste.” Google also has guidelines to prohibit apps that facilitate harassment and characteristics tied to systemic discrimination.

In recent years, there have been 13 billion visits to the Absher app, 11 million users and more than 110,00 million services done, according to Absher officials quoted in local Saudi media.