Apple notoriously keeps a vice-like grip over the types of applications it lets into its App Store. But still, when an app called Drones+ that compiles news of U.S. drone strikes was mysteriously rejected this week for a third time, technology critics were left puzzled — as was the app's creator. Here's what you should know: 

What is the app exactly?
It's a "simple enough idea for an iPhone app," say Christina Bonnington and Spencer Ackerman at Wired. Drones+ sends users a pop-up notice "whenever a flying robot kills someone in one of America's many undeclared wars." The "bare-bones application," which is fed by news reports that are inevitably published long after the drones actually strike, charts the location of the strikes on a Google-powered map, aggregating publicly available news from Pakistan, Yemen, and Somalia. It doesn't show any graphic images of dead bodies or any other residual damage from the aftermath. (Watch a demonstration below.)

Who made the app?
Drones+ was created by Josh Begley, a developer and student at New York University who wants to raise public awareness regarding the American government's use of unmanned aircraft strikes. "I wanted to have a more granular sense of what drone strikes really did look like, out of genuine curiosity," Begley tells The New York Times

Why was Drones+ rejected?
Apple charges a small team of reviewers with sifting through up to 10,000 apps a week and deciding what gets approved and what doesn't. Typically, the team "errs on the side of caution" if an app's content is questionable, say Bonnington and Ackerman. The first time Drones+ was submitted for review, for example, Apple said the app wasn't "useful or entertaining enough," so Begley added new features, like the ability to push alerts to users. Then Apple rejected the app a second time due to the prominence of Google's logo on the map. Drones+ was rejected the third time for violating provision 16.1 of the App Store guidelines, which doesn't allow for "excessively objectionable or crude content." It's incredibly frustrating, says Begley. The app is "literally just an aggregation of news. I don't know how to change that." 

What's next for Drones+?
Time will tell. Begley's "basic idea was to see if he could get App Store denizens a bit more interested in the U.S.' secretive, robotic wars," say Bonnington and Ackerman, "with information on those wars popping up on their phones the same way an Instagram comment or retweet might." Instead, Begley is considering porting his creation over to Android and its less stringent marketplace. 

Sources: CNETThe New York TimesTUAWWired