What happens when an app becomes so popular it's basically a public utility? For a school project, Shir Yadid and Meital Ben-Sinai, fourth-year students at Technion-Israel Institute of Technology,hacked the incredibly popular Waze GPS map, an Israeli-made smartphone app that provides directions and alerts drivers to traffic and accidents. The studentscreated avirtual traffic jamto showhow malicious hackers mightcreate a real one.

Disaster City is your one-stop for about every catastrophe you can think of. Train derailments, hurricanes, and other unfortunate happenings all get simulated at the Texas A&M site. As part of a test Wednesday, first responders test piloted something new: a smartphone app that detects radiation.

At a recent TED talk, inventor Myshkin Ingawale - who's best known for developing a needle-free test for hemoglobin - got some laughs when he unveiled his latest project. It's revolutionary, he said, and will one day put your future "in the toilet."

West Virginia has launched a smartphone app that's one part clever crowdsourcing and community engagement and one part sinister report-on-your-neighbor Big Brotherism. The Suspicious Activity Reporting Application is exactly what it sounds like. See something that looks like a violation of the law, no matter how insignificant? Snap a pic, tag it with GPS, and anonymously report it to the state. Parking illegally will never be the same.

Texting while driving can be deadly. Talking while walking? Also deadly. Or at least threatening enough that researchers at Dartmouth and the University of Bologna thought it necessary to develop a smartphone app that makes it safer. Their Android app uses machine learning and image recognition that takes place right on your phone to alert you when you're chatting your way right into an oncoming smash-up.