Following President Donald Trump's threats to annex Greenland, Danish consumers have turned to their smartphones to stage a massive grassroots boycott. The app "NonUSA" (also known as UdenUSA) has made a historic leap in the Danish App Store, surging from rank 441 to #1 in less than two weeks. Another tool, "Made O'Meter," has also broken into the top five, as users seek to identify and avoid American-made goods. These apps allow shoppers to scan product barcodes to confirm