The Problem Gambling Foundation has concerns with a new Lotto app which allows people to play scratchie-like games on their smartphones.
Lotto's new 'Instant Play' allows players to spend up to $50 a week on the phone app.
A spokesperson for the foundation, Andree Froude, said although the app checked to ensure players were over the age of 18 the games did appear to target a younger demographic.
"It is actually quite a pokie-like experience when you go and play them," she said.
"You're clicking a button, and you're getting a result and they are for that reason quite addictive and can be potentially very harmful."
She said it was a more harmful form of gambling than buying lotto tickets.
"These games are instant play and you get the result very quickly, and for that reason they are much more harmful than just going to purchase a lotto ticket."
The app is also restricted on Android phones due to Google's policy to exclude gambling apps, and requires security settings to be disabled to allow installation.
Ms Froude said it was important that people realised they were gambling when using the app, not just playing computer games.