COPENHAGEN, Denmark (AP) — The makers of mobile apps designed to help shoppers identify and boycott American goods say they saw a surge of interest in Denmark and beyond after the recent flare-up in tensions over U.S. President Donald Trump’s designs on Greenland.

The creator of the “Made O’Meter” app, Ian Rosenfeldt, said he saw around 30,000 downloads of the free app in just three days at the height of the trans-Atlantic diplomatic crisis in late January out of more than 100,000 since it was launched in March.

Apps offer practical help

Rosenfeldt, who lives in Copenhagen and works in digital marketing, decided to create the app a year ago after joining a Facebook group of like-minded Danes hoping to boycott U.S. goods.

“Many people were frustrated and thinking, ‘How do we actually do this in practical terms,’” the 53-year-old recalled. “If you use a bar code scanner, it’s difficult to see if a product is actually American or not, if it’s Danish or not. And if you don’t know that, you can’t really make a conscious choice.”

The latest version of “Made O’Meter” uses artificial intelligence to identify and analyze several products at a time, then recommend similar European-made alternatives. Users can set preferences, like “No USA-owned brands” or “Only EU-based brands.” The app claims over 95% accuracy.

“By using artificial intelligence, you can take an image of a product … and it can make a deep dive to go out and find the correct information about the product in many levels,” Rosenfeldt told The Associated Press during a demonstration at a Copenhagen grocery store. “This way, you have information that you can use to take decisions on what you think is right.”

‘Losing an ally’

After an initial surge of downloads when the app was launched, usage tailed off. Until last month, when Trump stepped up his rhetoric about the need for the U.S. to acquire Greenland, a strategically important and mineral-rich Arctic island that is a semiautonomous territory of Denmark.

Usage peaked Jan. 23, when there were almost 40,000 scans in one day, compared with 500 or so daily last summer. It has dropped back since but there were still around 5,000 a day this week, said Rosenfeldt, who noted “Made O’Meter” is used by over 20,000 people in Denmark but also by people in Germany, Spain, Italy, even Venezuela.

“It’s become much more personal,” said Rosenfeldt, who spoke of “losing an ally and a friend.”

Trump announced in January he would slap new tariffs on Denmark and seven other European countries that opposed his takeover calls, only to abruptly drop his threats after he said a “framework” for a deal over access to mineral-rich Greenland was reached with NATO Secretary-General Mark Rutte’s help. Few details of that agreement have emerged.