The company also showed off an array of products including AirTags to find lost items and podcast subscription services.

AirTags will cost $A45 each or four for $A149 while the iMac will start at $A1899 including GST.

Both will be available starting on April 30.

Apple introduced a thinner version of its iMac computer that uses its house-designed central processor unit and comes in seven colours including purple and green.

With a 61-cm display, the iMacs are just 11.5mm thick.

The new iMacs also feature a higher quality front-facing camera and microphone array, responding to complaints from consumers during the pandemic that the computer's cameras had not kept pace with the company's iPhones and iPads during an era of pervasive video calls.

The company also announced podcast subscription services that will compete with rival Spotify.

Subscription prices will be set by creators and billed monthly, Apple said.

Apple also updated its Apple TV set top box with better colour output and a faster processor chip.

The new Apple TV 4K will also let users improve a TV's picture by using light sensors on the iPhone.

Apple said that spouses and partners would be able to share and merge credit lines with its Apple Card, which CEO Tim Cook described as an important step toward making it easier for people to build their credit scores.

The AirTag announcement could result in a new round of complaints to US lawmakers that Apple is hurting smaller rivals.

Tile, a start-up that has sold a competing tracker for nearly a decade, last year testified before the US House of Representatives that Apple's App Store rules had made it harder to use Tile's products and will be called before the US Senate to testify on Wednesday.

Apple has said it subjects all apps, including its own, to the same App Store review rules.

Bob O'Donnell, head of TECHnalysis Research, said he does not believe the trackers will become a big business on their own.

"Because they are so late to this, it might not be that much different than when Apple got into set top boxes like Apple TV. They're a player. They're there but they're not huge," he said.

But Bajarin said the trackers could keep people tied to their iPhones if they rely on them to find items like keys and wallets.

"The more you buy into just one hardware product, the less likely it is you'll ever leave," Bajarin said.

Australian Associated Press