At Cammeray's Only About Children centre, preschool isn't what it used to be.

Friday marks five years since the advent of the iPad – Apple's handheld, mobile touchscreen device that delivered technology into the laps of babes. Literally. Parents are buying babies tablets for their first birthdays, says University of Western Sydney early education expert Dr Joanne Orlando. Toddlers who can't use the potty can nimbly swipe and tap their way through games and apps. Technology has changed early childhood in a very short time.

"It's a generation now that's been born into it," says Rebecca Watson, the director of Children's Services at Only About Children, where iPad use is part of the curriculum. "Kids take it for granted and we're the ones – parents – who are a little more challenged by it."

At the Cammeray campus, the children play with apps and games and use iPads for "research": in short, supervised sessions each day. Recently they used the devices to research Elsa's castle in the kids' movie Frozen – looking up "turrets" for example – in order to build one out of cardboard. Integrating the device as part of group time with clear criteria around use has "managed to avoid the kids becoming obsessed with them," Watson says.

The change wrought by touchscreen devices has been so rapid and pervasive – a quarter of a billion iPads have sold in five years, not to mention its imitators – that research has barely caught up. The benefits are obvious – to parents, at least: kids love them, learn new things quickly, and tend to be absorbed and quiet while playing them.

"I always compare it to a playground on screen," says Dr Orlando. "It's about investigating, curiosity, finding things out – all that while getting lots of skills and knowledge."

But there are negatives too. A study in the US journal Pediatrics in January suggested kids with heavy iPad use might be missing out on developing crucial social skills including empathy and behaviour regulation. "Much remains unknown," they warned.

The question is how to ensure very young kids are benefiting from their access to the devices at such a crucial time in their development, says Dr Irina Verenikina from the University of Wollongong. Her research suggests app design is key: repetitive, restrictive apps could be bad for kids, while apps that encourage imagination are good. Apps marketed as "educational" are not always better – imaginative play is the key thing for two-to-five-year-olds' cognitive development, she says.

Parents should play alongside kids, and resist using the tablet as a babysitter, researchers say. Screentime should be restricted and balanced with physical and other play. Parents should consider what apps are requiring of their kids, Watson says, and choose ones that are creative or fun, that exercise memory or matching skills.

Some parents are still holding out. Melanie Houston from Erskineville says her four-year-old daughter Adeline does not use the family's iPad. "As far as I'm concerned she has her whole life to be exposed to iPads, phones, computers. In a few years technology will be a huge part of her life and I have no doubt it will literally take her five minutes to master."