Almost half of Irish secondary school children describe themselves as being "addicted" to smartphones.
A survey of more than 2,600 Irish secondary school students by Studyclix.ie also found 54pc of teens use phones in class behind teachers' backs.
Meanwhile, almost one in 10 secondary school students has signed up for dating app Tinder.
The research confirms that kids now depend on their phones for large chunks of their social lives.
Snapchat is the most popular social media service among Irish teens, with 91pc of school-going survey respondents saying they use the messaging platform. This is ahead of Instagram (84pc), Facebook (80pc) and Whatsapp (53pc). Twitter continues its struggle among teenagers, with just 42pc of respondents saying they use the service.
Almost two thirds of students say they use their phones "too much", according to the survey.
"As a teacher myself, I think that the prevalence of smart phones in schools is the biggest challenge facing our profession," Luke Saunders, co-founder of Studyclix.ie, said.
"Like most of us, teenagers feel the need to check their phone repeatedly throughout the school day. It doesn't surprise me that more than half checked their phone in class in the last seven days."
The research also found over half of all sixth-year girls (53pc) do not participate in PE classes compared to an abstention rate of just 15pc among second years. Some 76pc of students say they would be prepared to pay back some money for student loans after college, with 39pc saying repayments of between €150 and €170 would be reasonable.
Of the 2,623 students questioned, 69pc were female, while 31pc were male. Almost half (46pc) were sixth-year students, while 18pc were fifth-year students and 24pc were third-year students.
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