U.S. Government Contractor Embedded Software in Apps to Track Phones

If a U.S. government contractor can do this, then what are China (e.g. TikTok), Russia, North Korea, Iran capable of?

"A small U.S. company with ties to the U.S. defense and intelligence communities has embedded its software in numerous mobile apps, allowing it to track the movements of hundreds of millions of mobile phones world-wide, according to interviews and documents reviewed by The Wall Street Journal. ..."

U.S. Government Contractor Embedded Software in Apps to Track Phones - WSJ Anomaly Six has ties to military, intelligence agencies and draws location data from more than 500 apps with hundreds of millions of users