Persistence, it turns out, does pay off. After rejecting it five times, Apple has finally approved an app that tracks every U.S. drone strike and sends a push notification to users every time a flying robot carries out a deadly mission around the world.

Josh Begley, the data artist and developer who made the app, finally got through Apple's careful approval process on Friday, more than a year and a half after the first rejection by the company's App Review Team.

It took persistence, but it took also some semantic trickery. Begley got the app approved because he removed the word "drone" from the name of the app and from its description. For the first three attempts, it was called Drones+, then Dronestream for the last two. This latest, successful time, it's called Metadata+, and Begley initially submitted it with no content or functionality, adding the archive of strikes later.

With those simple gimmicks, the app got the green light from Apple, which didn't raise any qualms about it.

That wasn't the case on the five previous attempts.

Begley created the app in the summer of 2012, submitting it on July 10, 2012. After almost two weeks, Apple rejected it, saying the app was "not useful or entertaining enough," and "did not appeal to a broad enough audience," which went against the App Store Review Guidelines, according to screenshots of the rejection message, which Begley shared with Mashable.

The second rejection, on Aug. 9, came because the app used Google Maps images without the "associated Google branding." The third time, on Aug. 27, it was because the app contained content that "many audiences would find objectionable."

At that point, Begley seemed to give up.

"If the content is found to be objectionable, and it’s literally just an aggregation of news, I don’t know how to change that," Begley told Wired at the time.

That's when Begley moved on to other projects, like tweeting every drone strike the U.S. has carried out, or mapping every American military base in the world.

Then, one year later, he tried again. This time he changed the name of the app to Dronestream and resubmitted it twice, on Sept. 10 and Sept. 17, 2013. That didn't work out — the app got rejected another two times two months later.

But Begley also received an email from an Apple Review Team employee on Sept. 23, asking him if he could talk on the phone regarding the app, according to a screenshot of the email.

When the employee called, she asked whether the app was about U.S. drone strikes, according to Begley's recount of the phone call. Begley answered that indeed, it was.

"If it's going to be about that specifically, it's not going to be approved," the employee answered, according to Begley. "But if you broaden your topic, then we can take another look. You know, there are certain concepts that we decide not to move forward with, and this is one."

At the beginning of 2014, Begley decided to give it another try. First, he created an empty app called "Ephemeral" and submitted it on Jan. 17 as an experiment. "The point of it was to have no content at all," he told Mashable.

The app was "quietly accepted," as Begley puts it, just five days later. So on Jan. 22 he submitted yet another empty app called "Metadata+" which promised "real-time updates on national security."

A tweet by Esquire's Tom Junod was the inspiration for the app's new name:

What's the big deal about Metadata? Our government kills people on the basis of Metadata. That's "the signature" in a signature strike. — Tom Junod (@TomJunod) June 7, 2013

As with the previous test app, this one went through after just six days — no objections on usefulness or questionable content this time. At that point, all Begley had to do was fill the app with the historical archive of drone strikes.

Now, apart from some design improvements, the app looks exactly as it did originally.

Apple didn't respond to Mashable's request for comment — it usually doesn't comment on its app review process — so it's unclear why the app was not rejected this time. But for Begley, it was never about Apple or the review process.

"At the end of the day, of course, the app is not about Apple or Android or the process for approving apps," Begley said. "It’s about tracking and mapping covert war. Like @dronestream, I want it to be a living archive of hauntings — those which ghost the landscapes we create, and those which ghost the landscapes some of us will never have to see."