Cyberbullying is a huge issue for young people. A UK study last year of more than 10,000 people aged 12 to 20 found 70% of respondents admitted to being abusive to someone else online.

Cyberbullying is particularly pernicious, because unlike traditional face-to-face bullying at school that can be left behind after the final bell, online harassment that lives and spreads on social media sites follows you wherever you go. But one young coder has created a “by kids, for kids” solution to the problem.

Trisha Prabhu came up with an app that aims to eradicate bullying messages before they’re sent, which she says has reached millions of students around the world already.

Watch the short film on the BBC website.