Apple and Google have been accused of helping to "enforce gender apartheid" in Saudi Arabia, by offering a sinister app that allows men to track women and stop them leaving the country.
Absher also has benign functions — like paying parking fines — but its travel features have been identified by activists and refugees as a major factor in the continued difficulty women have leaving Saudi Arabia.
Neither Apple nor Google responded to repeated requests for comment from INSIDER over several days before the publication of this article.
INSIDER reported on the existence of Absher last week, along with the story of Shahad Al Mohaimeed, a Saudi teen refugee who evaded the system to claim asylum in Sweden.
This is a screenshot from a desktop version of Absher, with added labels to explain its functions:
Since the story was published, Human Rights Watch and Amnesty International have both expressed concern about Google's and Apple's roles in hosting the app, which has been installed on smartphones more than 1 million times.
Human Rights Watch told INSIDER: "Apple and Google have rules against apps that facilitate threats and harassment.
"Apps like this one can facilitate human rights abuses, including discrimination against women."
Amnesty International told INSIDER that the SMS alerts are "another example of how the Saudi Arabian government has produced tools to limit women's freedoms."
It called on Apple and Google to accept that the app is being used to harm women, and demand changes to stop it happening in the future.
Yasmine Mohammed, a former Muslim and an outspoken critic of Saudi Arabia, told INSIDER that the companies are "facilitating the most archaic misogyny" and help the Saudi government to enforce "gender apartheid."
According to the Google Play store, Absher has been downloaded on Android devices more than 1 million times. Apple does not disclose download figures for apps.
The alert system, which can be set up inside Absher, is one of the main reasons women trying to flee Saudi Arabia get caught, according to activists.
The function tips off male guardians while the fleeing women can still be apprehended, according to Taleb Al Abdulmohsen, a Saudi refugee who sought asylum in Germany.
Adam Coogle, a Middle East researcher at Human Rights Watch, also told INSIDER about the SMS alerts and corroborated Al Abdulmohsen's story.
Here are the criticisms of Google and Apple in full:
Rothna Begum, Middle East researcher for Human Rights Watch:
"Apple and Google have rules against apps that facilitate threats and harassment. Apps like this one can facilitate human rights abuses, including discrimination against women.
"In evaluating whether an app should be allowed, app store providers should be considering the broader context of the purpose of the app, how it is used in practice, and whether it facilitates serious abuses. Companies should apply extra scrutiny to government-operated apps in particular.
"Even though the app is more general purpose, the government could simply remove the guardianship tracking functionality from the app, and continue to offer the rest of the functionality. (In other words, we wouldn't say that governments shouldn't be able to offer government services through mobile apps, just not services that facilitate abuses.)"
Dana Ahmed, Saudi Arabia researcher for Amnesty International:
"We call on these companies to assess the risk of human rights abuses and mitigate harm that these apps may have on women.
"This is another example of how the Saudi Arabian government has produced tools to limit women's freedoms.
"The tracking of women in this way curtails their movement and once again highlights the disturbing system of discrimination under the guardianship laws."
Yasmine Mohammed, a former Muslim and a women's-rights activist:
"There's a definite tragedy in the world's most technologically progressive platforms, Apple and Google, facilitating the most archaic misogyny.
"What irony. In the West these technologies are used to improve lives and in Saudi Arabia they're used to enforce gender apartheid."