However, those who use the app say it is still home to a robust market for illicit substances. Grindr, by far the world’s most popular gay dating app with an estimated 3 million daily users, has previously taken steps to address the buying, selling and promoting of drugs on its platform. “Today with Grindr, men can have sex and drugs delivered to their door instantly,” Phil McCabe, a social worker and president of the National Association of LGBT Addiction Professionals, told NBC News.