National Numeracy has developed a game based in a virtual film set with the player taking on the role of runner on their first day of work.
The game - Star Dash Studios - requires players to use everyday maths to tackle problems involving money, percentages, measurements and estimates.
The free game is aimed at 16- to 25-year-olds.
National Numeracy says teenagers need to learn to apply maths in practical contexts and see the relevance of it to their everyday lives.
It hopes introducing maths by stealth will help youngsters engage with the subject.
The charity's chief executive, Mike Ellicock, said: "All the evidence shows that too many teenagers feel disengaged from school maths and don't see its relevance to their future lives.
"We urgently need to crack this problem - and that means a better thought through approach to functional maths, in order to build young people's confidence, interest and practical skills.
"It's against this background that we have developed our new app.
"This is the perfect medium for persuading young people that numeracy is part of every job - whether that's on a film set, in an office or on a building site."
Anne Haworth, who chairs the Association of Teachers of Mathematics's general council said:  "National Numeracy does great work in schools, in the community and in the workplace, helping people to be more confident and competent in their use of everyday mathematics.
"I would expect the app to be a useful means of engaging learners of all ages with numeracy, which can only be a good thing."
A maths charity hopes its new mobile gaming app will help boost numeracy skills among young people.