School principals are warning parents about an anonymous chat app linked to cyberbullying which is sweeping Irish classrooms. Several schools have sent letters or text messages to parents in recent days asking them to discuss use of the SimSimi app with their children. The app allows users to view anonymous – and often insulting – messages left about them by typing in their name.

SimSimi is the most downloaded app in Ireland on Apple’s iTunes charts and the second most-downloaded app on the Google Play store.

One Dublin secondary school told parents this weekend that the app allowed individuals to be targeted easily. “We request that you use the weekend to discuss the possible fall-out of the use/misuse of this particular app with you children,” one senior member of staff warned parents.

In another secondary school, parents were sent text messages to warn about cyberbullying and inappropriate messages linked to use of the app. “Please check your sons / daughters use of this app and monitor same. We do not wish any students to be the targets of inappropriate messages,” the school advised.

Amusement and alarm Harry McCann, a secondary school student and founder of the Digital Youth Council, said the app was causing a mixture of amusement and alarm among students. “There is an awful lot of interest in it. Some people seem to think it’s funny, but students who’ve contacted us are very worried about it . . . It seems to have the sole purpose of insulting and demoralising people,” the 18-year-old said. “We’re planning to raise this at the Government’s data protection forum soon to see what can be done from a safety perspective.”

Many students have taken to Twitter and other social media networks to criticise internet firms for allowing the app to be downloaded and to warn others about downloading it.

“SimSimi is a disgusting app and should be banned. Why do people even make apps like this – literally an app for promoting bullying,” wrote one student.

“When you say my name on SimSimi, ‘autism’ comes up . . . people are so unfunny and cruel when hiding behind a phone screen,” wrote another student.

The South Korean company that developed SimSimi did not respond to requests for comment on Sunday.

The app, which was developed over a decade ago, has topped download charts in Ireland in recent days. It works by using a combination of artificial intelligence and used-generated content.

Relevant response When a user sends a message on their phone, the app responds by scanning for related conversations in its database and responds by spitting out a relevant response.

Ironically, the app was first marketed as a “fun, playful robot”, though much of the content now appears to be vulgar or obscene.

The popularity of the app comes at a time of rising concern over the impact of cyberbullying on young people.

Some 14 per cent of primary school children and 10 per cent secondary school children have been cyberbullied, according to research conducted by Dublin City University’s national anti-bullying research and resource centre.