Google says it doesn't comment on specific apps, but the insurgent group's most recent atrocities include gang rapes, mass murder and house-to-house searches in the city of Kunduz, according to Amnesty International. It was first spotted on Play by the US-based Intel Group, which monitors jihadist social network activity. The group may be trying to take a page from ISIS, which has lured fighters and suicide bombers from Europe and elsewhere on social media. A Taliban spokesman told Bloomberg that the app "is part of our advanced technological efforts to make more global audience [sic]."

Google received a half-million app submissions last year alone, meaning it's required to screen thousands per day. Still, the search giant implemented an app review process for the Play store last year, so it's not clear how an app from a terrorist group slipped through initially.