If you’re an American, this may seem ridiculous but Iceland is a country with a small population and an even smaller gene pool.

Nidhi Subbaraman of NBC News reports.

Anti-incest app built by Iceland college students

A group of students at the University of Iceland in Reykjavík have created an Android app that prevents Icelanders from accidentally dating their cousins.

The app draws information from the Íslendingabók database, a national record of Iceland residents and family trees dating back into the Middle Ages.

Arnar Aðalsteinsson, Alexander Helgason and Hákon Björnsson, in their final year at the University of Iceland, entered and won an app-building contest sponsored by the tenders of the Íslendingabók database.

When you tap phones with someone who has the app, it brings up an alert if the owners of the two phones share a grandparent. (Of course, if you don’t already know who you share a grandparent with, incest may be the least of your problems, but the team says it is looking into functionality for spotting common great grandparents, too.)

The feature is called “Sifjaspellsspillir” which directly translates to “Incest Destroyer,” though the team prefers the phrase “Incest Spoiler.”

The app has been downloaded 3,651 times at their last check, the team told NBC News. An app for the iPhone is very likely on the way, they say.

“Genealogy is the kind of the national hobby of Iceland,” Friðrik Skúlason, a software engineer who first started building the Íslendingabók database in the 1980s, told NBC News. “On average if you pick two people on the street at random you will find they are related 6 or 7 generations back.”