Three teens, siblings, built an app for rating cops. It's called Five-O and it wants to prevent another shooting, if possible.

Caleb Christian is 14 years old. He's concerned about the growing number of incidents involving police abuse in the news but he also knows that there are good cops in various communities in the country. However, he doesn't have a way to figure out where the good ones are so he created Five-O with the help of his sisters, Ima, 16, and Asha, 15.

"We had been hearing a lot about the scary and negative issues occurring in the media. Most recently, the Michael Brown case, and we talk to our parents often about these issues, and they really try to put everything into context for us. One of the things they really stress is that we focus on finding solutions," said Ima Christian.

Five-O is essentially an app that allows users to record and rate their interactions with members of the police force. Think of it like Yelp for cops. After an encounter, users can open the app to "grade" the police officer, rating them from A to F. There are dropdown boxes that can be filled out if any physical or verbal abuse happened, as well as space for including other details about the incident. Users can also check out ratings for other police departments in the country and participate in forums to talk to others. Five-O also has a Q&A section called "Know Your Rights" to inform people of what they are entitled to.

But while the app was inspired by negative events, Five-O is not designed to simply out bad cops. In the same way that a bad experience with a cop can be documented, a good one can also be recorded to give credit where credit is due. A feature that allows police to respond to lodged complaints is planned to be added in the future.

Five-O is not the first app involving police action in communities but it is the latest in a series of tools that have been created with the aim of monitoring the police. In 2012, the New York Civil Liberties Union also released an app for documenting stop-and-frisks to determine if the New York Police Department is specifically targeting people of color.

Five-O is the first app that the Christians made but they have two more in development under their company Pine Tart, Inc. There's Froshyly, designed to connect college freshmen together, and Coily, a review app for hair-care products for black women.

Five-O is only available on Android devices.